diff --git a/signxml/processor.py b/signxml/processor.py
index 1903b36..011d588 100644
--- a/signxml/processor.py
+++ b/signxml/processor.py
@@ -1,6 +1,5 @@
 import logging
 import os
-import warnings
 from typing import Any, List, Tuple
 from xml.etree import ElementTree as stdlibElementTree
 
@@ -53,10 +52,10 @@ def get_root(self, data):
             # TODO: add debug level logging statement re: performance impact here
             return self._fromstring(stdlibElementTree.tostring(data, encoding="utf-8"))
         else:
-            # HACK: deep copy won't keep root's namespaces resulting in an invalid digest
-            # We use a copy so we can modify the tree
-            # TODO: turn this off for xmlenc
-            return self._fromstring(etree.tostring(data))
+            # Create a separate copy of the node so we can modify the tree and avoid any c14n inconsistencies from
+            # namespaces propagating from parent nodes. The lxml docs recommend using copy.deepcopy for this, but it
+            # doesn't seem to preserve namespaces. It would be nice to find a less heavy-handed way of doing this.
+            return self._fromstring(self._tostring(data))
 
 
 class XMLSignatureProcessor(XMLProcessor):
@@ -126,10 +125,6 @@ def _c14n(self, nodes, algorithm: CanonicalizationMethod, inclusive_ns_prefixes=
                 inclusive_ns_prefixes=inclusive_ns_prefixes,
             )
         if exclusive is False and self.excise_empty_xmlns_declarations is True:
-            warnings.warn(
-                "excise_empty_xmlns_declarations is deprecated and will be removed in a future SignXML release",
-                DeprecationWarning,
-            )
             # Incorrect legacy behavior. See also:
             # - https://github.com/XML-Security/signxml/issues/193
             # - http://www.w3.org/TR/xml-c14n, "namespace axis"
diff --git a/signxml/verifier.py b/signxml/verifier.py
index 841ecd5..7f43c5a 100644
--- a/signxml/verifier.py
+++ b/signxml/verifier.py
@@ -210,6 +210,12 @@ def _apply_transforms(self, payload, *, transforms_node: etree._Element, signatu
             except ValueError:
                 continue
             inclusive_ns_prefixes = self._get_inclusive_ns_prefixes(transform)
+
+            # Create a separate copy of the node so we can modify the tree and avoid any c14n inconsistencies from
+            # namespaces propagating from parent nodes. The lxml docs recommend using copy.deepcopy for this, but it
+            # doesn't seem to preserve namespaces. It would be nice to find a less heavy-handed way of doing this.
+            payload = self._fromstring(self._tostring(payload))
+
             payload = self._c14n(
                 payload, algorithm=c14n_algorithm_from_transform, inclusive_ns_prefixes=inclusive_ns_prefixes
             )
diff --git a/test/test.py b/test/test.py
index 50b5ec0..69782d1 100755
--- a/test/test.py
+++ b/test/test.py
@@ -640,6 +640,16 @@ def test_payload_c14n(self):
             b'<abc xmlns="http://example.com"><foo xmlns="">bar</foo></abc>',
         )
 
+    def test_xmlns_insulation_of_reference_c14n(self):
+        cert, key = self.load_example_keys()
+        doc = etree.fromstring(
+            '<rDE xmlns="http://example.com/ns1">'
+            '<DE Id="target"><dDVId>9</dDVId><gOpeDE><iTipEmi>1</iTipEmi></gOpeDE></DE>'
+            "</rDE>"
+        )
+        root = XMLSigner().sign(doc, cert=cert, key=key, reference_uri="#target")
+        XMLVerifier().verify(root, x509_cert=cert)
+
     def test_verify_config(self):
         data = etree.parse(self.example_xml_files[0]).getroot()
         cert, key = self.load_example_keys()