diff --git a/tests/definitions_test.py b/tests/definitions_test.py
index dce19f84a..ab5f61fab 100644
--- a/tests/definitions_test.py
+++ b/tests/definitions_test.py
@@ -1,4 +1,4 @@
-from test_configuration import COMPONENT_TYPES, IMAGE_FILETYPES, SCHEMAS, KNOWN_SLUGS, ROOT_DIR, USE_LOCAL_KNOWN_SLUGS, NETBOX_DT_LIBRARY_URL
+from test_configuration import COMPONENT_TYPES, IMAGE_FILETYPES, SCHEMAS, KNOWN_SLUGS, ROOT_DIR, USE_LOCAL_KNOWN_SLUGS, NETBOX_DT_LIBRARY_URL, KNOWN_MODULES
 import pickle_operations
 from yaml_loader import DecimalSafeLoader
 from device_types import DeviceType, ModuleType, verify_filename, validate_components
@@ -110,10 +110,12 @@ image_files = _get_image_files()
 
 if USE_LOCAL_KNOWN_SLUGS:
     KNOWN_SLUGS = pickle_operations.read_pickle_data(f'{ROOT_DIR}/tests/known-slugs.pickle')
+    KNOWN_MODULES = pickle_operations.read_pickle_data(f'{ROOT_DIR}/tests/known-modules.pickle')
 else:
     temp_dir = tempfile.TemporaryDirectory()
     repo = Repo.clone_from(url=NETBOX_DT_LIBRARY_URL, to_path=temp_dir.name)
     KNOWN_SLUGS = pickle_operations.read_pickle_data(f'{temp_dir.name}/tests/known-slugs.pickle')
+    KNOWN_MODULES = pickle_operations.read_pickle_data(f'{temp_dir.name}/tests/known-modules.pickle')
 
 @pytest.mark.parametrize(('file_path', 'schema'), definition_files)
 def test_definitions(file_path, schema):
@@ -159,7 +161,7 @@ def test_definitions(file_path, schema):
         assert this_device.verify_slug(KNOWN_SLUGS), pytest.fail(this_device.failureMessage, False)
 
     # Verify the filename is valid. Must either be the model or part_number.
-    assert verify_filename(this_device), pytest.fail(this_device.failureMessage, False)
+    assert verify_filename(this_device, (KNOWN_MODULES if not this_device.isDevice else None)), pytest.fail(this_device.failureMessage, False)
 
     # Check for duplicate components within the definition
     assert validate_components(COMPONENT_TYPES, this_device), pytest.fail(this_device.failureMessage, False)
diff --git a/tests/device_types.py b/tests/device_types.py
index 7b58cd0e7..8b6b9321f 100644
--- a/tests/device_types.py
+++ b/tests/device_types.py
@@ -151,7 +151,7 @@ class ModuleType:
             slugified = slugified[:-1]
         return slugified
 
-def verify_filename(device: (DeviceType or ModuleType)):
+def verify_filename(device: (DeviceType or ModuleType), KNOWN_MODULES: (set or None)):
     head, tail = os.path.split(device.get_filepath())
     filename = tail.rsplit(".", 1)[0].casefold()
 
@@ -159,6 +159,12 @@ def verify_filename(device: (DeviceType or ModuleType)):
         device.failureMessage = f'{device.file_path} file name is invalid. Must be either the model "{device._slug_model}" or part_number "{device.part_number} / {device._slug_part_number}"'
         return False
 
+    if not device.isDevice:
+        matches = [file_name for file_name, file_path in KNOWN_MODULES if file_name.casefold() == filename.casefold()]
+        if len(matches) > 1:
+            device.failureMessage = f'{device.file_path} appears to be duplicated. Found {len(matches)} matches: {", ".join(matches)}'
+            return False
+
     return True
 
 def validate_components(component_types, device_or_module):
diff --git a/tests/generate-slug-list.py b/tests/generate-slug-list.py
index 7cf3f1d0e..cb901c559 100644
--- a/tests/generate-slug-list.py
+++ b/tests/generate-slug-list.py
@@ -6,18 +6,18 @@ import decimal
 from yaml_loader import DecimalSafeLoader
 from jsonschema import Draft4Validator, RefResolver
 from jsonschema.exceptions import ValidationError
-from test_configuration import SCHEMAS, KNOWN_SLUGS, ROOT_DIR
+from test_configuration import SCHEMAS, KNOWN_SLUGS, ROOT_DIR, KNOWN_MODULES
 from urllib.request import urlopen
 import pickle_operations
 
-def _get_device_type_files():
+def _get_type_files(device_or_module):
     """
     Return a list of all definition files within the specified path.
     """
     file_list = []
 
     for path, schema in SCHEMAS:
-        if path == 'device-types':
+        if path == f'{device_or_module}-types':
             # Initialize the schema
             with open(f"{ROOT_DIR}/schema/{schema}") as schema_file:
                 schema = json.loads(schema_file.read(),
@@ -75,8 +75,8 @@ def load_file(file_path, schema):
 
     return (True, definition)
 
-def _generate_known_slugs():
-    all_files = _get_device_type_files()
+def _generate_knowns(device_or_module):
+    all_files = _get_type_files(device_or_module)
 
     for file_path, schema in all_files:
         definition_status, definition = load_file(file_path, schema)
@@ -84,7 +84,13 @@ def _generate_known_slugs():
             print(definition)
             exit(1)
 
-        KNOWN_SLUGS.add((definition.get('slug'), file_path))
+        if device_or_module == 'device':
+            KNOWN_SLUGS.add((definition.get('slug'), file_path))
+        else:
+            KNOWN_MODULES.add((os.path.splitext(os.path.basename(file_path))[0], os.path.dirname(file_path)))
 
-_generate_known_slugs()
-pickle_operations.write_pickle_data(KNOWN_SLUGS, f'{ROOT_DIR}/tests/known-slugs.pickle')
\ No newline at end of file
+_generate_knowns('device')
+pickle_operations.write_pickle_data(KNOWN_SLUGS, f'{ROOT_DIR}/tests/known-slugs.pickle')
+
+_generate_knowns('module')
+pickle_operations.write_pickle_data(KNOWN_MODULES, f'{ROOT_DIR}/tests/known-modules.pickle')
\ No newline at end of file
diff --git a/tests/known-modules.pickle b/tests/known-modules.pickle
new file mode 100644
index 000000000..4fad73ab6
Binary files /dev/null and b/tests/known-modules.pickle differ
diff --git a/tests/test_configuration.py b/tests/test_configuration.py
index 5f90a0f44..b2835790a 100644
--- a/tests/test_configuration.py
+++ b/tests/test_configuration.py
@@ -24,6 +24,7 @@ COMPONENT_TYPES = (
 ROOT_DIR = os.path.abspath(os.path.join(os.path.dirname( __file__ ), '..'))
 
 KNOWN_SLUGS = set()
+KNOWN_MODULES = set()
 
 USE_LOCAL_KNOWN_SLUGS = False