diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index b4c957c78..fbf71742e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -32,6 +32,7 @@ Additionally, be sure to adhere to the following style guidance:
 * Use two spaces for indenting.
 * Specify a device type's attributes before listing its components.
 * Avoid encapsulating YAML values in quotes unless necessary to avoid a syntax error.
+* End each definition file with a blank line.
 
 ## The Contribution Workflow
 
diff --git a/tests/test_definitions.py b/tests/test_definitions.py
index 5cc4cc219..8898a4b04 100644
--- a/tests/test_definitions.py
+++ b/tests/test_definitions.py
@@ -32,14 +32,20 @@ def test_environment():
 @pytest.mark.parametrize("file_path", _get_definition_files())
 def test_definition(file_path):
     """
-    Validate DeviceType definitions using the provided JSON schema.
+    Validate each DeviceType definition file using the provided JSON schema.
     """
     # Check file extension
     assert file_path.split('.')[-1] in ('yaml', 'yml'), f"Invalid file extension: {file_path}"
 
     # Read file
     with open(file_path) as definition_file:
-        definition = yaml.load(definition_file.read(), Loader=yaml.SafeLoader)
+        content = definition_file.read()
+
+        # Check for trailing newline
+        assert content[-1] == '\n', "Missing trailing newline"
+
+        # Load YAML data
+        definition = yaml.load(content, Loader=yaml.SafeLoader)
 
     # Run validation
     try: