diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2ec68794f8..6c2c755e55 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@
 - Warn if container access is denied ([#2270](https://github.com/nf-core/tools/pull/2270))
 - Error if module container specification has quay.io as prefix when it shouldn't have ([#2278])(https://github.com/nf-core/tools/pull/2278/files)
 - Detect if container is 'simple name' and try to contact quay.io server by default ([#2281](https://github.com/nf-core/tools/pull/2281))
+- Warn about null/None/empty default values in `nextflow_schema.json` ([#3328](https://github.com/nf-core/tools/pull/2328))
 
 ### Modules
 
diff --git a/nf_core/schema.py b/nf_core/schema.py
index 75dbebce04..b00697334b 100644
--- a/nf_core/schema.py
+++ b/nf_core/schema.py
@@ -238,6 +238,11 @@ def validate_default_params(self):
             jsonschema.validate(self.schema_defaults, schema_no_required)
         except jsonschema.exceptions.ValidationError as e:
             raise AssertionError(f"Default parameters are invalid: {e.message}")
+        for param, default in self.schema_defaults.items():
+            if default in ("null", "", None, "None"):
+                log.warning(
+                    f"[yellow][!] Default parameter '{param}' is empty or null. It is advisable to remove the default from the schema"
+                )
         log.info("[green][✓] Default parameters match schema validation")
 
         # Make sure every default parameter exists in the nextflow.config and is of correct type