diff --git a/CHANGELOG.md b/CHANGELOG.md
index f84b0618990..c25e0af1354 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,7 @@ Contributors:
 ### Under the hood
 - Bump werkzeug upper bound dependency to `<v2.0` ([#3011](https://github.com/fishtown-analytics/dbt/pull/3011))
 - Performance fixes for many different things ([#2862](https://github.com/fishtown-analytics/dbt/issues/2862), [#3034](https://github.com/fishtown-analytics/dbt/pull/3034))
+- Update code to use Mashumaro 2.0 ([#3138](https://github.com/fishtown-analytics/dbt/pull/3138))
 
 Contributors:
 - [@Bl3f](https://github.com/Bl3f) ([#3011](https://github.com/fishtown-analytics/dbt/pull/3011))
diff --git a/core/dbt/adapters/base/relation.py b/core/dbt/adapters/base/relation.py
index d8905615f0a..5a30dec3fe3 100644
--- a/core/dbt/adapters/base/relation.py
+++ b/core/dbt/adapters/base/relation.py
@@ -45,7 +45,7 @@ def _get_field_named(cls, field_name):
     def __eq__(self, other):
         if not isinstance(other, self.__class__):
             return False
-        return self.to_dict() == other.to_dict()
+        return self.to_dict(omit_none=True) == other.to_dict(omit_none=True)
 
     @classmethod
     def get_default_quote_policy(cls) -> Policy:
@@ -185,10 +185,10 @@ def quoted(self, identifier):
     def create_from_source(
         cls: Type[Self], source: ParsedSourceDefinition, **kwargs: Any
     ) -> Self:
-        source_quoting = source.quoting.to_dict()
+        source_quoting = source.quoting.to_dict(omit_none=True)
         source_quoting.pop('column', None)
         quote_policy = deep_merge(
-            cls.get_default_quote_policy().to_dict(),
+            cls.get_default_quote_policy().to_dict(omit_none=True),
             source_quoting,
             kwargs.get('quote_policy', {}),
         )
diff --git a/core/dbt/compilation.py b/core/dbt/compilation.py
index 7afb3e20d74..0b36cd0664f 100644
--- a/core/dbt/compilation.py
+++ b/core/dbt/compilation.py
@@ -138,7 +138,7 @@ def write_graph(self, outfile: str, manifest: Manifest):
         """
         out_graph = self.graph.copy()
         for node_id in self.graph.nodes():
-            data = manifest.expect(node_id).to_dict()
+            data = manifest.expect(node_id).to_dict(omit_none=True)
             out_graph.add_node(node_id, **data)
         nx.write_gpickle(out_graph, outfile)
 
@@ -339,7 +339,7 @@ def _recursively_prepend_ctes(
             model.compiled_sql = injected_sql
         model.extra_ctes_injected = True
         model.extra_ctes = prepended_ctes
-        model.validate(model.to_dict())
+        model.validate(model.to_dict(omit_none=True))
 
         manifest.update_node(model)
 
@@ -388,7 +388,7 @@ def _compile_node(
 
         logger.debug("Compiling {}".format(node.unique_id))
 
-        data = node.to_dict()
+        data = node.to_dict(omit_none=True)
         data.update({
             'compiled': False,
             'compiled_sql': None,
diff --git a/core/dbt/config/profile.py b/core/dbt/config/profile.py
index 256198929ff..8ba78ad7aad 100644
--- a/core/dbt/config/profile.py
+++ b/core/dbt/config/profile.py
@@ -111,8 +111,8 @@ def to_profile_info(
             'credentials': self.credentials,
         }
         if serialize_credentials:
-            result['config'] = self.config.to_dict()
-            result['credentials'] = self.credentials.to_dict()
+            result['config'] = self.config.to_dict(omit_none=True)
+            result['credentials'] = self.credentials.to_dict(omit_none=True)
         return result
 
     def to_target_dict(self) -> Dict[str, Any]:
@@ -125,7 +125,7 @@ def to_target_dict(self) -> Dict[str, Any]:
             'name': self.target_name,
             'target_name': self.target_name,
             'profile_name': self.profile_name,
-            'config': self.config.to_dict(),
+            'config': self.config.to_dict(omit_none=True),
         })
         return target
 
@@ -138,7 +138,7 @@ def __eq__(self, other: object) -> bool:
     def validate(self):
         try:
             if self.credentials:
-                dct = self.credentials.to_dict()
+                dct = self.credentials.to_dict(omit_none=True)
                 self.credentials.validate(dct)
             dct = self.to_profile_info(serialize_credentials=True)
             ProfileConfig.validate(dct)
diff --git a/core/dbt/config/project.py b/core/dbt/config/project.py
index fe9ca743ce5..908199d36b6 100644
--- a/core/dbt/config/project.py
+++ b/core/dbt/config/project.py
@@ -347,7 +347,7 @@ def create_project(self, rendered: RenderComponents) -> 'Project':
         # break many things
         quoting: Dict[str, Any] = {}
         if cfg.quoting is not None:
-            quoting = cfg.quoting.to_dict()
+            quoting = cfg.quoting.to_dict(omit_none=True)
 
         models: Dict[str, Any]
         seeds: Dict[str, Any]
@@ -578,10 +578,11 @@ def to_project_config(self, with_packages=False):
             'config-version': self.config_version,
         })
         if self.query_comment:
-            result['query-comment'] = self.query_comment.to_dict()
+            result['query-comment'] = \
+                self.query_comment.to_dict(omit_none=True)
 
         if with_packages:
-            result.update(self.packages.to_dict())
+            result.update(self.packages.to_dict(omit_none=True))
 
         return result
 
diff --git a/core/dbt/config/runtime.py b/core/dbt/config/runtime.py
index ea3c028e506..a2380210334 100644
--- a/core/dbt/config/runtime.py
+++ b/core/dbt/config/runtime.py
@@ -78,7 +78,7 @@ def from_parts(
             get_relation_class_by_name(profile.credentials.type)
             .get_default_quote_policy()
             .replace_dict(_project_quoting_dict(project, profile))
-        ).to_dict()
+        ).to_dict(omit_none=True)
 
         cli_vars: Dict[str, Any] = parse_cli_vars(getattr(args, 'vars', '{}'))
 
@@ -391,7 +391,7 @@ def __getattribute__(self, name):
                 f"'UnsetConfig' object has no attribute {name}"
             )
 
-    def __post_serialize__(self, dct, options=None):
+    def __post_serialize__(self, dct):
         return {}
 
 
diff --git a/core/dbt/context/base.py b/core/dbt/context/base.py
index ca23ecdaad1..26eb6241b0d 100644
--- a/core/dbt/context/base.py
+++ b/core/dbt/context/base.py
@@ -538,4 +538,5 @@ def flags(self) -> Any:
 
 def generate_base_context(cli_vars: Dict[str, Any]) -> Dict[str, Any]:
     ctx = BaseContext(cli_vars)
+    # This is not a Mashumaro to_dict call
     return ctx.to_dict()
diff --git a/core/dbt/context/context_config.py b/core/dbt/context/context_config.py
index 80467ea70d3..2176056159b 100644
--- a/core/dbt/context/context_config.py
+++ b/core/dbt/context/context_config.py
@@ -196,7 +196,7 @@ def calculate_node_config_dict(
             base=base,
         )
         finalized = config.finalize_and_validate()
-        return finalized.to_dict()
+        return finalized.to_dict(omit_none=True)
 
 
 class UnrenderedConfigGenerator(BaseContextConfigGenerator[Dict[str, Any]]):
diff --git a/core/dbt/context/docs.py b/core/dbt/context/docs.py
index 2ea70135688..bdf66614ae9 100644
--- a/core/dbt/context/docs.py
+++ b/core/dbt/context/docs.py
@@ -77,4 +77,5 @@ def generate_runtime_docs(
     current_project: str,
 ) -> Dict[str, Any]:
     ctx = DocsRuntimeContext(config, target, manifest, current_project)
+    # This is not a Mashumaro to_dict call
     return ctx.to_dict()
diff --git a/core/dbt/context/providers.py b/core/dbt/context/providers.py
index 7515680ef19..2d9ee3bb208 100644
--- a/core/dbt/context/providers.py
+++ b/core/dbt/context/providers.py
@@ -1115,7 +1115,7 @@ def graph(self) -> Dict[str, Any]:
 
     @contextproperty('model')
     def ctx_model(self) -> Dict[str, Any]:
-        return self.model.to_dict()
+        return self.model.to_dict(omit_none=True)
 
     @contextproperty
     def pre_hooks(self) -> Optional[List[Dict[str, Any]]]:
@@ -1231,7 +1231,7 @@ def pre_hooks(self) -> List[Dict[str, Any]]:
         if isinstance(self.model, ParsedSourceDefinition):
             return []
         return [
-            h.to_dict() for h in self.model.config.pre_hook
+            h.to_dict(omit_none=True) for h in self.model.config.pre_hook
         ]
 
     @contextproperty
@@ -1239,7 +1239,7 @@ def post_hooks(self) -> List[Dict[str, Any]]:
         if isinstance(self.model, ParsedSourceDefinition):
             return []
         return [
-            h.to_dict() for h in self.model.config.post_hook
+            h.to_dict(omit_none=True) for h in self.model.config.post_hook
         ]
 
     @contextproperty
diff --git a/core/dbt/contracts/connection.py b/core/dbt/contracts/connection.py
index 86c6978c7a1..1a35f882641 100644
--- a/core/dbt/contracts/connection.py
+++ b/core/dbt/contracts/connection.py
@@ -132,7 +132,7 @@ def connection_info(
     ) -> Iterable[Tuple[str, Any]]:
         """Return an ordered iterator of key/value pairs for pretty-printing.
         """
-        as_dict = self.to_dict(options={'keep_none': True})
+        as_dict = self.to_dict(omit_none=False)
         connection_keys = set(self._connection_keys())
         aliases: List[str] = []
         if with_aliases:
@@ -148,8 +148,8 @@ def _connection_keys(self) -> Tuple[str, ...]:
         raise NotImplementedError
 
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data):
+        data = super().__pre_deserialize__(data)
         data = cls.translate_aliases(data)
         return data
 
@@ -159,7 +159,7 @@ def translate_aliases(
     ) -> Dict[str, Any]:
         return translate_aliases(kwargs, cls._ALIASES, recurse)
 
-    def __post_serialize__(self, dct, options=None):
+    def __post_serialize__(self, dct):
         # no super() -- do we need it?
         if self._ALIASES:
             dct.update({
diff --git a/core/dbt/contracts/graph/compiled.py b/core/dbt/contracts/graph/compiled.py
index c8f08710b94..177d041110b 100644
--- a/core/dbt/contracts/graph/compiled.py
+++ b/core/dbt/contracts/graph/compiled.py
@@ -178,7 +178,7 @@ def parsed_instance_for(compiled: CompiledNode) -> ParsedResource:
         raise ValueError('invalid resource_type: {}'
                          .format(compiled.resource_type))
 
-    return cls.from_dict(compiled.to_dict())
+    return cls.from_dict(compiled.to_dict(omit_none=True))
 
 
 NonSourceCompiledNode = Union[
diff --git a/core/dbt/contracts/graph/manifest.py b/core/dbt/contracts/graph/manifest.py
index ee24e62db84..d6000c88fd7 100644
--- a/core/dbt/contracts/graph/manifest.py
+++ b/core/dbt/contracts/graph/manifest.py
@@ -240,7 +240,7 @@ def build_edges(nodes: List[ManifestNode]):
 
 
 def _deepcopy(value):
-    return value.from_dict(value.to_dict())
+    return value.from_dict(value.to_dict(omit_none=True))
 
 
 class Locality(enum.IntEnum):
@@ -564,11 +564,11 @@ def build_flat_graph(self):
         """
         self.flat_graph = {
             'nodes': {
-                k: v.to_dict(options={'keep_none': True})
+                k: v.to_dict(omit_none=False)
                 for k, v in self.nodes.items()
             },
             'sources': {
-                k: v.to_dict(options={'keep_none': True})
+                k: v.to_dict(omit_none=False)
                 for k, v in self.sources.items()
             }
         }
@@ -755,7 +755,7 @@ def writable_manifest(self):
 
     # When 'to_dict' is called on the Manifest, it substitues a
     # WritableManifest
-    def __pre_serialize__(self, options=None):
+    def __pre_serialize__(self):
         return self.writable_manifest()
 
     def write(self, path):
diff --git a/core/dbt/contracts/graph/model_config.py b/core/dbt/contracts/graph/model_config.py
index 09370e5f563..580b24f8f03 100644
--- a/core/dbt/contracts/graph/model_config.py
+++ b/core/dbt/contracts/graph/model_config.py
@@ -307,7 +307,7 @@ def update_from(
         """
         # sadly, this is a circular import
         from dbt.adapters.factory import get_config_class_by_name
-        dct = self.to_dict(options={'keep_none': True})
+        dct = self.to_dict(omit_none=False)
 
         adapter_config_cls = get_config_class_by_name(adapter_type)
 
@@ -326,12 +326,12 @@ def update_from(
         return self.from_dict(dct)
 
     def finalize_and_validate(self: T) -> T:
-        dct = self.to_dict(options={'keep_none': True})
+        dct = self.to_dict(omit_none=False)
         self.validate(dct)
         return self.from_dict(dct)
 
     def replace(self, **kwargs):
-        dct = self.to_dict()
+        dct = self.to_dict(omit_none=True)
 
         mapping = self.field_mapping()
         for key, value in kwargs.items():
@@ -396,8 +396,8 @@ class NodeConfig(BaseConfig):
     full_refresh: Optional[bool] = None
 
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data):
+        data = super().__pre_deserialize__(data)
         field_map = {'post-hook': 'post_hook', 'pre-hook': 'pre_hook'}
         # create a new dict because otherwise it gets overwritten in
         # tests
@@ -414,8 +414,8 @@ def __pre_deserialize__(cls, data, options=None):
                 data[new_name] = data.pop(field_name)
         return data
 
-    def __post_serialize__(self, dct, options=None):
-        dct = super().__post_serialize__(dct, options=options)
+    def __post_serialize__(self, dct):
+        dct = super().__post_serialize__(dct)
         field_map = {'post_hook': 'post-hook', 'pre_hook': 'pre-hook'}
         for field_name in field_map:
             if field_name in dct:
@@ -480,7 +480,7 @@ def validate(cls, data):
         # formerly supported with GenericSnapshotConfig
 
     def finalize_and_validate(self):
-        data = self.to_dict()
+        data = self.to_dict(omit_none=True)
         self.validate(data)
         return self.from_dict(data)
 
diff --git a/core/dbt/contracts/graph/parsed.py b/core/dbt/contracts/graph/parsed.py
index a4020e2a487..fb62d805e27 100644
--- a/core/dbt/contracts/graph/parsed.py
+++ b/core/dbt/contracts/graph/parsed.py
@@ -99,8 +99,8 @@ class HasRelationMetadata(dbtClassMixin, Replaceable):
     # because it messes up the subclasses and default parameters
     # so hack it here
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data):
+        data = super().__pre_deserialize__(data)
         if 'database' not in data:
             data['database'] = None
         return data
@@ -141,7 +141,7 @@ def patch(self, patch: 'ParsedNodePatch'):
             # Maybe there should be validation or restrictions
             # elsewhere?
             assert isinstance(self, dbtClassMixin)
-            dct = self.to_dict(options={'keep_none': True})
+            dct = self.to_dict(omit_none=False)
             self.validate(dct)
 
     def get_materialization(self):
@@ -454,7 +454,7 @@ def patch(self, patch: ParsedMacroPatch):
         if flags.STRICT_MODE:
             # What does this actually validate?
             assert isinstance(self, dbtClassMixin)
-            dct = self.to_dict(options={'keep_none': True})
+            dct = self.to_dict(omit_none=False)
             self.validate(dct)
 
     def same_contents(self, other: Optional['ParsedMacro']) -> bool:
diff --git a/core/dbt/contracts/graph/unparsed.py b/core/dbt/contracts/graph/unparsed.py
index 165e22e4b1a..e6656c92a40 100644
--- a/core/dbt/contracts/graph/unparsed.py
+++ b/core/dbt/contracts/graph/unparsed.py
@@ -231,12 +231,9 @@ class UnparsedSourceTableDefinition(HasColumnTests, HasTests):
     external: Optional[ExternalTable] = None
     tags: List[str] = field(default_factory=list)
 
-    def __post_serialize__(self, dct, options=None):
+    def __post_serialize__(self, dct):
         dct = super().__post_serialize__(dct)
-        keep_none = False
-        if options and 'keep_none' in options and options['keep_none']:
-            keep_none = True
-        if not keep_none and self.freshness is None:
+        if 'freshness' not in dct and self.freshness is None:
             dct['freshness'] = None
         return dct
 
@@ -261,12 +258,9 @@ class UnparsedSourceDefinition(dbtClassMixin, Replaceable):
     def yaml_key(self) -> 'str':
         return 'sources'
 
-    def __post_serialize__(self, dct, options=None):
+    def __post_serialize__(self, dct):
         dct = super().__post_serialize__(dct)
-        keep_none = False
-        if options and 'keep_none' in options and options['keep_none']:
-            keep_none = True
-        if not keep_none and self.freshness is None:
+        if 'freshnewss' not in dct and self.freshness is None:
             dct['freshness'] = None
         return dct
 
@@ -290,7 +284,7 @@ class SourceTablePatch(dbtClassMixin):
     columns: Optional[Sequence[UnparsedColumn]] = None
 
     def to_patch_dict(self) -> Dict[str, Any]:
-        dct = self.to_dict()
+        dct = self.to_dict(omit_none=True)
         remove_keys = ('name')
         for key in remove_keys:
             if key in dct:
@@ -327,7 +321,7 @@ class SourcePatch(dbtClassMixin, Replaceable):
     tags: Optional[List[str]] = None
 
     def to_patch_dict(self) -> Dict[str, Any]:
-        dct = self.to_dict()
+        dct = self.to_dict(omit_none=True)
         remove_keys = ('name', 'overrides', 'tables', 'path')
         for key in remove_keys:
             if key in dct:
diff --git a/core/dbt/contracts/relation.py b/core/dbt/contracts/relation.py
index 6bcb58c749e..41eb22c3569 100644
--- a/core/dbt/contracts/relation.py
+++ b/core/dbt/contracts/relation.py
@@ -52,7 +52,7 @@ def __len__(self):
         return len(fields(self.__class__))
 
     def incorporate(self, **kwargs):
-        value = self.to_dict()
+        value = self.to_dict(omit_none=True)
         value = deep_merge(value, kwargs)
         return self.from_dict(value)
 
diff --git a/core/dbt/contracts/results.py b/core/dbt/contracts/results.py
index 43fc9117ce6..b021b767e2d 100644
--- a/core/dbt/contracts/results.py
+++ b/core/dbt/contracts/results.py
@@ -97,8 +97,8 @@ class BaseResult(dbtClassMixin):
     message: Optional[Union[str, int]]
 
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data):
+        data = super().__pre_deserialize__(data)
         if 'message' not in data:
             data['message'] = None
         return data
@@ -206,7 +206,7 @@ def from_execution_results(
         )
 
     def write(self, path: str):
-        write_json(path, self.to_dict(options={'keep_none': True}))
+        write_json(path, self.to_dict(omit_none=False))
 
 
 @dataclass
@@ -448,8 +448,8 @@ class CatalogResults(dbtClassMixin):
     errors: Optional[List[str]] = None
     _compile_results: Optional[Any] = None
 
-    def __post_serialize__(self, dct, options=None):
-        dct = super().__post_serialize__(dct, options=options)
+    def __post_serialize__(self, dct):
+        dct = super().__post_serialize__(dct)
         if '_compile_results' in dct:
             del dct['_compile_results']
         return dct
diff --git a/core/dbt/contracts/rpc.py b/core/dbt/contracts/rpc.py
index 213f13717bb..83d248e84d2 100644
--- a/core/dbt/contracts/rpc.py
+++ b/core/dbt/contracts/rpc.py
@@ -38,8 +38,8 @@ class RPCParameters(dbtClassMixin):
     timeout: Optional[float]
 
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data, omit_none=True):
+        data = super().__pre_deserialize__(data)
         if 'timeout' not in data:
             data['timeout'] = None
         if 'task_tags' not in data:
@@ -428,8 +428,8 @@ class TaskTiming(dbtClassMixin):
     # These ought to be defaults but superclass order doesn't
     # allow that to work
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data):
+        data = super().__pre_deserialize__(data)
         for field_name in ('start', 'end', 'elapsed'):
             if field_name not in data:
                 data[field_name] = None
@@ -496,8 +496,8 @@ class PollResult(RemoteResult, TaskTiming):
     # These ought to be defaults but superclass order doesn't
     # allow that to work
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
-        data = super().__pre_deserialize__(data, options=options)
+    def __pre_deserialize__(cls, data):
+        data = super().__pre_deserialize__(data)
         for field_name in ('start', 'end', 'elapsed'):
             if field_name not in data:
                 data[field_name] = None
diff --git a/core/dbt/contracts/util.py b/core/dbt/contracts/util.py
index c0743b62ecd..5dd329d193e 100644
--- a/core/dbt/contracts/util.py
+++ b/core/dbt/contracts/util.py
@@ -58,7 +58,7 @@ def merged(self, *args):
 class Writable:
     def write(self, path: str):
         write_json(
-            path, self.to_dict(options={'keep_none': True})  # type: ignore
+            path, self.to_dict(omit_none=False)  # type: ignore
         )
 
 
@@ -74,7 +74,7 @@ class AdditionalPropertiesMixin:
     # not in the class definitions and puts them in an
     # _extra dict in the class
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
+    def __pre_deserialize__(cls, data):
         # dir() did not work because fields with
         # metadata settings are not found
         # The original version of this would create the
@@ -93,18 +93,18 @@ def __pre_deserialize__(cls, data, options=None):
             else:
                 new_dict[key] = value
         data = new_dict
-        data = super().__pre_deserialize__(data, options=options)
+        data = super().__pre_deserialize__(data)
         return data
 
-    def __post_serialize__(self, dct, options=None):
-        data = super().__post_serialize__(dct, options=options)
+    def __post_serialize__(self, dct):
+        data = super().__post_serialize__(dct)
         data.update(self.extra)
         if '_extra' in data:
             del data['_extra']
         return data
 
     def replace(self, **kwargs):
-        dct = self.to_dict(options={'keep_none': True})
+        dct = self.to_dict(omit_none=False)
         dct.update(kwargs)
         return self.from_dict(dct)
 
diff --git a/core/dbt/dataclass_schema.py b/core/dbt/dataclass_schema.py
index 1382d489c50..630ce90e343 100644
--- a/core/dbt/dataclass_schema.py
+++ b/core/dbt/dataclass_schema.py
@@ -1,5 +1,5 @@
 from typing import (
-    Type, ClassVar, Dict, cast, TypeVar
+    Type, ClassVar, cast,
 )
 import re
 from dataclasses import fields
@@ -9,29 +9,28 @@
 
 from hologram import JsonSchemaMixin, FieldEncoder, ValidationError
 
+# type: ignore
 from mashumaro import DataClassDictMixin
-from mashumaro.types import SerializableEncoder, SerializableType
+from mashumaro.config import (
+    TO_DICT_ADD_OMIT_NONE_FLAG, BaseConfig as MashBaseConfig
+)
+from mashumaro.types import SerializableType, SerializationStrategy
 
 
-class DateTimeSerializableEncoder(SerializableEncoder[datetime]):
-    @classmethod
-    def _serialize(cls, value: datetime) -> str:
+class DateTimeSerialization(SerializationStrategy):
+    def serialize(self, value):
         out = value.isoformat()
         # Assume UTC if timezone is missing
         if value.tzinfo is None:
             out = out + "Z"
         return out
 
-    @classmethod
-    def _deserialize(cls, value: str) -> datetime:
+    def deserialize(self, value):
         return (
             value if isinstance(value, datetime) else parse(cast(str, value))
         )
 
 
-TV = TypeVar("TV")
-
-
 # This class pulls in both JsonSchemaMixin from Hologram and
 # DataClassDictMixin from our fork of Mashumaro. The 'to_dict'
 # and 'from_dict' methods come from Mashumaro. Building
@@ -43,23 +42,21 @@ class dbtClassMixin(DataClassDictMixin, JsonSchemaMixin):
        against the schema
     """
 
-    _serializable_encoders: ClassVar[Dict[str, SerializableEncoder]] = {
-        'datetime.datetime': DateTimeSerializableEncoder(),
-    }
+    class Config(MashBaseConfig):
+        code_generation_options = [
+            TO_DICT_ADD_OMIT_NONE_FLAG,
+        ]
+        serialization_strategy = {
+            datetime: DateTimeSerialization(),
+        }
+
     _hyphenated: ClassVar[bool] = False
     ADDITIONAL_PROPERTIES: ClassVar[bool] = False
 
     # This is called by the mashumaro to_dict in order to handle
     # nested classes.
     # Munges the dict that's returned.
-    def __post_serialize__(self, dct, options=None):
-        keep_none = False
-        if options and 'keep_none' in options and options['keep_none']:
-            keep_none = True
-        if not keep_none:  # remove attributes that are None
-            new_dict = {k: v for k, v in dct.items() if v is not None}
-            dct = new_dict
-
+    def __post_serialize__(self, dct):
         if self._hyphenated:
             new_dict = {}
             for key in dct:
@@ -75,7 +72,7 @@ def __post_serialize__(self, dct, options=None):
     # This is called by the mashumaro _from_dict method, before
     # performing the conversion to a dict
     @classmethod
-    def __pre_deserialize__(cls, data, options=None):
+    def __pre_deserialize__(cls, data):
         if cls._hyphenated:
             new_dict = {}
             for key in data:
@@ -92,8 +89,8 @@ def __pre_deserialize__(cls, data, options=None):
     # hologram and in mashumaro.
     def _local_to_dict(self, **kwargs):
         args = {}
-        if 'omit_none' in kwargs and kwargs['omit_none'] is False:
-            args['options'] = {'keep_none': True}
+        if 'omit_none' in kwargs:
+            args['omit_none'] = kwargs['omit_none']
         return self.to_dict(**args)
 
 
diff --git a/core/dbt/logger.py b/core/dbt/logger.py
index 1916f49020e..95b9699ec01 100644
--- a/core/dbt/logger.py
+++ b/core/dbt/logger.py
@@ -95,7 +95,8 @@ def __call__(self, record, handler):
         # utils imports exceptions which imports logger...
         import dbt.utils
         log_message = super().__call__(record, handler)
-        return json.dumps(log_message.to_dict(), cls=dbt.utils.JSONEncoder)
+        dct = log_message.to_dict(omit_none=True)
+        return json.dumps(dct, cls=dbt.utils.JSONEncoder)
 
 
 class FormatterMixin:
@@ -127,6 +128,7 @@ class OutputHandler(logbook.StreamHandler, FormatterMixin):
     The `format_string` parameter only changes the default text output, not
       debug mode or json.
     """
+
     def __init__(
         self,
         stream,
@@ -220,7 +222,8 @@ def __init__(self, timing_info: Optional[dbtClassMixin] = None):
 
     def process(self, record):
         if self.timing_info is not None:
-            record.extra['timing_info'] = self.timing_info.to_dict()
+            record.extra['timing_info'] = self.timing_info.to_dict(
+                omit_none=True)
 
 
 class DbtProcessState(logbook.Processor):
@@ -349,6 +352,7 @@ def make_log_dir_if_missing(log_dir):
 class DebugWarnings(logbook.compat.redirected_warnings):
     """Log warnings, except send them to 'debug' instead of 'warning' level.
     """
+
     def make_record(self, message, exception, filename, lineno):
         rv = super().make_record(message, exception, filename, lineno)
         rv.level = logbook.DEBUG
diff --git a/core/dbt/parser/base.py b/core/dbt/parser/base.py
index 7f603d02d61..d2b9d9cd100 100644
--- a/core/dbt/parser/base.py
+++ b/core/dbt/parser/base.py
@@ -252,7 +252,7 @@ def _create_parsetime_node(
             'raw_sql': block.contents,
             'unique_id': self.generate_unique_id(name),
             'config': self.config_dict(config),
-            'checksum': block.file.checksum.to_dict(),
+            'checksum': block.file.checksum.to_dict(omit_none=True),
         }
         dct.update(kwargs)
         try:
@@ -301,7 +301,7 @@ def update_parsed_node_config(
         self, parsed_node: IntermediateNode, config_dict: Dict[str, Any]
     ) -> None:
         # Overwrite node config
-        final_config_dict = parsed_node.config.to_dict()
+        final_config_dict = parsed_node.config.to_dict(omit_none=True)
         final_config_dict.update(config_dict)
         # re-mangle hooks, in case we got new ones
         self._mangle_hooks(final_config_dict)
diff --git a/core/dbt/parser/schemas.py b/core/dbt/parser/schemas.py
index f176a8e1731..1a165b7a452 100644
--- a/core/dbt/parser/schemas.py
+++ b/core/dbt/parser/schemas.py
@@ -385,7 +385,7 @@ def create_test_node(
             'config': self.config_dict(config),
             'test_metadata': test_metadata,
             'column_name': column_name,
-            'checksum': FileHash.empty().to_dict(),
+            'checksum': FileHash.empty().to_dict(omit_none=True),
         }
         try:
             ParsedSchemaTestNode.validate(dct)
diff --git a/core/dbt/parser/snapshots.py b/core/dbt/parser/snapshots.py
index 16e5c52ab0d..db977ab4c1d 100644
--- a/core/dbt/parser/snapshots.py
+++ b/core/dbt/parser/snapshots.py
@@ -68,7 +68,8 @@ def get_fqn(self, path: str, name: str) -> List[str]:
 
     def transform(self, node: IntermediateSnapshotNode) -> ParsedSnapshotNode:
         try:
-            parsed_node = ParsedSnapshotNode.from_dict(node.to_dict())
+            dct = node.to_dict(omit_none=True)
+            parsed_node = ParsedSnapshotNode.from_dict(dct)
             self.set_snapshot_attributes(parsed_node)
             return parsed_node
         except ValidationError as exc:
diff --git a/core/dbt/parser/sources.py b/core/dbt/parser/sources.py
index 30f018f6029..b6ef559ffd2 100644
--- a/core/dbt/parser/sources.py
+++ b/core/dbt/parser/sources.py
@@ -49,8 +49,8 @@ def patch_source(
         if patch is None:
             return unpatched
 
-        source_dct = unpatched.source.to_dict()
-        table_dct = unpatched.table.to_dict()
+        source_dct = unpatched.source.to_dict(omit_none=True)
+        table_dct = unpatched.table.to_dict(omit_none=True)
         patch_path: Optional[Path] = None
 
         source_table_patch: Optional[SourceTablePatch] = None
diff --git a/core/dbt/rpc/builtins.py b/core/dbt/rpc/builtins.py
index 7e900ca5357..a7ac1d77879 100644
--- a/core/dbt/rpc/builtins.py
+++ b/core/dbt/rpc/builtins.py
@@ -177,7 +177,7 @@ def poll_complete(
 
 
 def _dict_logs(logs: List[LogMessage]) -> List[Dict[str, Any]]:
-    return [log.to_dict() for log in logs]
+    return [log.to_dict(omit_none=True) for log in logs]
 
 
 class Poll(RemoteBuiltinMethod[PollParameters, PollResult]):
diff --git a/core/dbt/rpc/response_manager.py b/core/dbt/rpc/response_manager.py
index 1d44f7e0cbe..a1beb1810f6 100644
--- a/core/dbt/rpc/response_manager.py
+++ b/core/dbt/rpc/response_manager.py
@@ -97,7 +97,7 @@ def _get_responses(cls, requests, dispatcher):
                     # Note: errors in to_dict do not show up anywhere in
                     # the output and all you get is a generic 500 error
                     output.result = \
-                        output.result.to_dict(options={'keep_none': True})
+                        output.result.to_dict(omit_none=False)
             yield output
 
     @classmethod
diff --git a/core/dbt/rpc/task_handler.py b/core/dbt/rpc/task_handler.py
index c657f4e3de7..ce2f320fc1f 100644
--- a/core/dbt/rpc/task_handler.py
+++ b/core/dbt/rpc/task_handler.py
@@ -391,7 +391,7 @@ def get_result(self) -> RemoteResult:
             except RPCException as exc:
                 # RPC Exceptions come already preserialized for the jsonrpc
                 # framework
-                exc.logs = [log.to_dict() for log in self.logs]
+                exc.logs = [log.to_dict(omit_none=True) for log in self.logs]
                 exc.tags = self.tags
                 raise
 
diff --git a/core/dbt/task/generate.py b/core/dbt/task/generate.py
index 86c3ac57b85..e37041e39a1 100644
--- a/core/dbt/task/generate.py
+++ b/core/dbt/task/generate.py
@@ -114,8 +114,8 @@ def make_unique_id_map(
                 if unique_id in sources:
                     dbt.exceptions.raise_ambiguous_catalog_match(
                         unique_id,
-                        sources[unique_id].to_dict(),
-                        table.to_dict(),
+                        sources[unique_id].to_dict(omit_none=True),
+                        table.to_dict(omit_none=True),
                     )
                 else:
                     sources[unique_id] = table.replace(unique_id=unique_id)
diff --git a/core/dbt/task/list.py b/core/dbt/task/list.py
index 5f91cf052a7..d78223eef8b 100644
--- a/core/dbt/task/list.py
+++ b/core/dbt/task/list.py
@@ -110,7 +110,7 @@ def generate_json(self):
         for node in self._iterate_selected_nodes():
             yield json.dumps({
                 k: v
-                for k, v in node.to_dict(options={'keep_none': True}).items()
+                for k, v in node.to_dict(omit_none=False).items()
                 if k in self.ALLOWED_KEYS
             })
 
diff --git a/core/dbt/task/printer.py b/core/dbt/task/printer.py
index 7313e4c9b0b..917d545d77f 100644
--- a/core/dbt/task/printer.py
+++ b/core/dbt/task/printer.py
@@ -169,7 +169,7 @@ def print_snapshot_result_line(
 
     info, status, logger_fn = get_printable_result(
         result, 'snapshotted', 'snapshotting')
-    cfg = model.config.to_dict()
+    cfg = model.config.to_dict(omit_none=True)
 
     msg = "{info} {description}".format(
         info=info, description=description, **cfg)
diff --git a/core/dbt/task/run.py b/core/dbt/task/run.py
index 0fbbdde0e4d..e397551cd8f 100644
--- a/core/dbt/task/run.py
+++ b/core/dbt/task/run.py
@@ -117,7 +117,7 @@ def track_model_run(index, num_nodes, run_model_result):
         "hashed_contents": utils.get_hashed_contents(
             run_model_result.node
         ),
-        "timing": [t.to_dict() for t in run_model_result.timing],
+        "timing": [t.to_dict(omit_none=True) for t in run_model_result.timing],
     })
 
 
@@ -193,7 +193,7 @@ def _build_run_model_result(self, model, context):
         result = context['load_result']('main')
         adapter_response = {}
         if isinstance(result.response, dbtClassMixin):
-            adapter_response = result.response.to_dict()
+            adapter_response = result.response.to_dict(omit_none=True)
         return RunResult(
             node=model,
             status=RunStatus.Success,
diff --git a/core/dbt/utils.py b/core/dbt/utils.py
index c4618a7ef27..031a53c6e7a 100644
--- a/core/dbt/utils.py
+++ b/core/dbt/utils.py
@@ -320,7 +320,7 @@ def default(self, obj):
         if hasattr(obj, 'to_dict'):
             # if we have a to_dict we should try to serialize the result of
             # that!
-            return obj.to_dict()
+            return obj.to_dict(omit_none=True)
         return super().default(obj)
 
 
diff --git a/core/setup.py b/core/setup.py
index 7e2ec6c1713..5eb29bdc0b5 100644
--- a/core/setup.py
+++ b/core/setup.py
@@ -72,6 +72,7 @@ def read(fname):
         'dataclasses==0.6;python_version<"3.7"',
         'hologram==0.0.13',
         'logbook>=1.5,<1.6',
+        'mashumaro==2.0',
         'typing-extensions>=3.7.4,<3.8',
         # the following are all to match snowflake-connector-python
         'requests>=2.18.0,<2.24.0',
diff --git a/dev_requirements.txt b/dev_requirements.txt
index 2feffaf4b9e..a7887c64529 100644
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -13,5 +13,3 @@ mypy==0.782
 wheel
 twine
 pytest-logbook>=1.2.0,<1.3
-git+https://github.com/fishtown-analytics/dbt-mashumaro.git@dbt-customizations
-jsonschema
diff --git a/test/unit/test_bigquery_adapter.py b/test/unit/test_bigquery_adapter.py
index 00a4ef3b885..9e74afdd569 100644
--- a/test/unit/test_bigquery_adapter.py
+++ b/test/unit/test_bigquery_adapter.py
@@ -659,7 +659,7 @@ def test_parse_partition_by(self):
         self.assertEqual(
             adapter.parse_partition_by({
                 "field": "ts",
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "date",
                 "granularity": "day"
@@ -670,7 +670,7 @@ def test_parse_partition_by(self):
             adapter.parse_partition_by({
                 "field": "ts",
                 "data_type": "date",
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "date",
                 "granularity": "day"
@@ -683,7 +683,7 @@ def test_parse_partition_by(self):
                 "data_type": "date",
                 "granularity": "MONTH"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "date",
                 "granularity": "MONTH"
@@ -696,7 +696,7 @@ def test_parse_partition_by(self):
                 "data_type": "date",
                 "granularity": "YEAR"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "date",
                 "granularity": "YEAR"
@@ -709,7 +709,7 @@ def test_parse_partition_by(self):
                 "data_type": "timestamp",
                 "granularity": "HOUR"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "timestamp",
                 "granularity": "HOUR"
@@ -722,7 +722,8 @@ def test_parse_partition_by(self):
                 "data_type": "timestamp",
                 "granularity": "MONTH"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True
+                ), {
                 "field": "ts",
                 "data_type": "timestamp",
                 "granularity": "MONTH"
@@ -735,7 +736,7 @@ def test_parse_partition_by(self):
                 "data_type": "timestamp",
                 "granularity": "YEAR"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "timestamp",
                 "granularity": "YEAR"
@@ -748,7 +749,7 @@ def test_parse_partition_by(self):
                 "data_type": "datetime",
                 "granularity": "HOUR"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "datetime",
                 "granularity": "HOUR"
@@ -761,7 +762,7 @@ def test_parse_partition_by(self):
                 "data_type": "datetime",
                 "granularity": "MONTH"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "datetime",
                 "granularity": "MONTH"
@@ -774,7 +775,7 @@ def test_parse_partition_by(self):
                 "data_type": "datetime",
                 "granularity": "YEAR"
 
-            }).to_dict(), {
+            }).to_dict(omit_none=True), {
                 "field": "ts",
                 "data_type": "datetime",
                 "granularity": "YEAR"
@@ -795,7 +796,8 @@ def test_parse_partition_by(self):
                     "end": 100,
                     "interval": 20
                 }
-            }).to_dict(), {
+            }).to_dict(omit_none=True
+                ), {
                 "field": "id",
                 "data_type": "int64",
                 "granularity": "day",
diff --git a/test/unit/test_config.py b/test/unit/test_config.py
index 60754702c31..12858baeec4 100644
--- a/test/unit/test_config.py
+++ b/test/unit/test_config.py
@@ -776,7 +776,7 @@ def test_all_overrides(self):
                 LocalPackage(local='foo'),
                 GitPackage(git='git@example.com:fishtown-analytics/dbt-utils.git', revision='test-rev')
             ]))
-        str(project)
+        str(project)  # this does the equivalent of project.to_project_config(with_packages=True)
         json.dumps(project.to_project_config())
 
     def test_string_run_hooks(self):
diff --git a/test/unit/test_contracts_graph_parsed.py b/test/unit/test_contracts_graph_parsed.py
index 7e968ed9fe5..f2fb11b3abd 100644
--- a/test/unit/test_contracts_graph_parsed.py
+++ b/test/unit/test_contracts_graph_parsed.py
@@ -1618,7 +1618,7 @@ def test_timestamp_snapshot_ok(basic_timestamp_snapshot_dict, basic_timestamp_sn
 
     assert_symmetric(node, node_dict, ParsedSnapshotNode)
     assert_symmetric(inter, node_dict, IntermediateSnapshotNode)
-    assert ParsedSnapshotNode.from_dict(inter.to_dict()) == node
+    assert ParsedSnapshotNode.from_dict(inter.to_dict(omit_none=True)) == node
     assert node.is_refable is True
     assert node.is_ephemeral is False
     pickle.loads(pickle.dumps(node))
@@ -1631,7 +1631,7 @@ def test_check_snapshot_ok(basic_check_snapshot_dict, basic_check_snapshot_objec
 
     assert_symmetric(node, node_dict, ParsedSnapshotNode)
     assert_symmetric(inter, node_dict, IntermediateSnapshotNode)
-    assert ParsedSnapshotNode.from_dict(inter.to_dict()) == node
+    assert ParsedSnapshotNode.from_dict(inter.to_dict(omit_none=True)) == node
     assert node.is_refable is True
     assert node.is_ephemeral is False
     pickle.loads(pickle.dumps(node))
diff --git a/test/unit/test_docs_generate.py b/test/unit/test_docs_generate.py
index 96dc568ff88..49576e9e100 100644
--- a/test/unit/test_docs_generate.py
+++ b/test/unit/test_docs_generate.py
@@ -32,7 +32,7 @@ def generate_catalog_dict(self, columns):
             sources=sources,
             errors=None,
         )
-        return result.to_dict(options={'keep_none': True})['nodes']
+        return result.to_dict(omit_none=False)['nodes']
 
     def test__unflatten_empty(self):
         columns = {}
diff --git a/test/unit/test_manifest.py b/test/unit/test_manifest.py
index c88c6c2178e..a776837e609 100644
--- a/test/unit/test_manifest.py
+++ b/test/unit/test_manifest.py
@@ -212,9 +212,9 @@ def setUp(self):
             ),
         }
         for node in self.nested_nodes.values():
-            node.validate(node.to_dict())
+            node.validate(node.to_dict(omit_none=True))
         for source in self.sources.values():
-            source.validate(source.to_dict())
+            source.validate(source.to_dict(omit_none=True))
 
         os.environ['DBT_ENV_CUSTOM_ENV_key'] = 'value'
 
@@ -229,7 +229,7 @@ def test__no_nodes(self):
             metadata=ManifestMetadata(generated_at=datetime.utcnow()),
         )
         self.assertEqual(
-            manifest.writable_manifest().to_dict(),
+            manifest.writable_manifest().to_dict(omit_none=True),
             {
                 'nodes': {},
                 'sources': {},
@@ -258,7 +258,7 @@ def test__nested_nodes(self):
             exposures={}, selectors={},
             metadata=ManifestMetadata(generated_at=datetime.utcnow()),
         )
-        serialized = manifest.writable_manifest().to_dict()
+        serialized = manifest.writable_manifest().to_dict(omit_none=True)
         self.assertEqual(serialized['metadata']['generated_at'], '2018-02-14T09:15:13Z')
         self.assertEqual(serialized['docs'], {})
         self.assertEqual(serialized['disabled'], [])
@@ -371,7 +371,7 @@ def test_no_nodes_with_metadata(self, mock_user):
                             metadata=metadata, files={}, exposures={})
 
         self.assertEqual(
-            manifest.writable_manifest().to_dict(),
+            manifest.writable_manifest().to_dict(omit_none=True),
             {
                 'nodes': {},
                 'sources': {},
@@ -612,7 +612,7 @@ def test__no_nodes(self):
         manifest = Manifest(nodes={}, sources={}, macros={}, docs={}, selectors={},
                             disabled=[], metadata=metadata, files={}, exposures={})
         self.assertEqual(
-            manifest.writable_manifest().to_dict(),
+            manifest.writable_manifest().to_dict(omit_none=True),
             {
                 'nodes': {},
                 'macros': {},
@@ -640,7 +640,7 @@ def test__nested_nodes(self):
                             disabled=[], selectors={},
                             metadata=ManifestMetadata(generated_at=datetime.utcnow()),
                             files={}, exposures={})
-        serialized = manifest.writable_manifest().to_dict()
+        serialized = manifest.writable_manifest().to_dict(omit_none=True)
         self.assertEqual(serialized['metadata']['generated_at'], '2018-02-14T09:15:13Z')
         self.assertEqual(serialized['disabled'], [])
         parent_map = serialized['parent_map']
diff --git a/test/unit/utils.py b/test/unit/utils.py
index 96bb0e2f140..fe26e472042 100644
--- a/test/unit/utils.py
+++ b/test/unit/utils.py
@@ -145,7 +145,7 @@ def setUp(self):
         super().setUp()
 
     def assert_to_dict(self, obj, dct):
-        self.assertEqual(obj.to_dict(), dct)
+        self.assertEqual(obj.to_dict(omit_none=True), dct)
 
     def assert_from_dict(self, obj, dct, cls=None):
         if cls is None:
@@ -185,7 +185,7 @@ def compare_dicts(dict1, dict2):
 
 
 def assert_to_dict(obj, dct):
-    assert obj.to_dict() == dct
+    assert obj.to_dict(omit_none=True) == dct
 
 
 def assert_from_dict(obj, dct, cls=None):
diff --git a/third-party-stubs/mashumaro/config.pyi b/third-party-stubs/mashumaro/config.pyi
new file mode 100644
index 00000000000..04a5cb1070b
--- /dev/null
+++ b/third-party-stubs/mashumaro/config.pyi
@@ -0,0 +1,10 @@
+from mashumaro.types import SerializationStrategy as SerializationStrategy
+from typing import Any, Callable, Dict, List, Union
+
+TO_DICT_ADD_OMIT_NONE_FLAG: str
+SerializationStrategyValueType = Union[SerializationStrategy, Dict[str, Union[str, Callable]]]
+
+class BaseConfig:
+    debug: bool = ...
+    code_generation_options: List[str] = ...
+    serialization_strategy: Dict[Any, SerializationStrategyValueType] = ...
diff --git a/third-party-stubs/mashumaro/serializer/base/dict.pyi b/third-party-stubs/mashumaro/serializer/base/dict.pyi
index 568079dac8e..6a1e53f18c8 100644
--- a/third-party-stubs/mashumaro/serializer/base/dict.pyi
+++ b/third-party-stubs/mashumaro/serializer/base/dict.pyi
@@ -2,10 +2,15 @@ from typing import Any, Mapping, Dict, Optional
 
 class DataClassDictMixin:
     def __init_subclass__(cls, **kwargs: Any) -> None: ...
-    def __pre_serialize__(self, options: Optional[Dict[str, Any]]) -> Any: ...
-    def __post_serialize__(self, dct: Mapping, options: Optional[Dict[str, Any]]) -> Any: ...
+    def __pre_serialize__(self) -> Any: ...
+    def __post_serialize__(self, dct: Mapping) -> Any: ...
     @classmethod
-    def __pre_deserialize__(cls: Any, dct: Mapping, options: Optional[Dict[str, Any]]) -> Any: ...
-    def to_dict( self, use_bytes: bool = False, use_enum: bool = False, use_datetime: bool = False, options: Optional[Dict[str, Any]] = None) -> dict: ...
+    def __pre_deserialize__(cls: Any, dct: Mapping) -> Any: ...
+    # This is absolutely totally wrong. This is *not* the signature of the Mashumaro to_dict
+    # But mypy insists that the DataClassDictMixin to_dict and the JsonSchemaMixin to_dict
+    # must have the same signatures now that we have an 'omit_none' flag on the Mashumaro to_dict.
+    # There is no 'validate = False' in Mashumaro.
+    # Could not find a way to tell mypy to ignore it.
+    def to_dict( self, omit_none = False, validate = False) -> dict: ...  
     @classmethod
-    def from_dict( cls, d: Mapping, use_bytes: bool = False, use_enum: bool = False, use_datetime: bool = False, options: Optional[Dict[str, Any]] = None) -> Any: ...
+    def from_dict( cls, d: Mapping, use_bytes: bool = False, use_enum: bool = False, use_datetime: bool = False) -> Any: ...