diff --git a/tests/unit/test_registry.py b/tests/unit/test_registry.py
index 7554f7b08..91872d343 100644
--- a/tests/unit/test_registry.py
+++ b/tests/unit/test_registry.py
@@ -85,10 +85,28 @@ async def async_test_function(num: int) -> int:
                 )
             )
 
+        # Create a file for the deprecated function
+        with open(os.path.join(tmp_path, "deprecated_function.py"), "w") as f:
+            f.write(
+                textwrap.dedent(
+                    """
+                from tracecat_registry import registry
+
+                @registry.register(
+                    description="This is a deprecated function",
+                    namespace="test",
+                    deprecated="This function is deprecated",
+                )
+            """
+                )
+            )
+
         yield test_module
+
     finally:
         # Clean up
         del sys.modules["test_module"]
+        del sys.modules["test_deprecated_module"]
 
 
 def test_udf_can_be_registered(mock_package):
@@ -122,6 +140,18 @@ def test_udf_validate_args(mock_package):
         udf.validate_args(num="not a number")
 
 
+def test_deprecated_function_can_be_registered(mock_deprecated_package):
+    """Test that a deprecated function can be registered."""
+    repo = Repository()
+    repo._register_udfs_from_package(mock_deprecated_package)
+
+    udf = repo.get("test.deprecated_function")
+    assert udf is not None
+
+    # Check descriptors
+    assert udf.deprecated == "This function is deprecated"
+
+
 def test_registry_function_can_be_called(mock_package):
     """We need to test that the ordering of the workflow tasks is correct."""
     repo = Repository()