diff --git a/scripts/clean_metadata.py b/scripts/clean_metadata.py
index 0a9bcb2be..73ba2b713 100755
--- a/scripts/clean_metadata.py
+++ b/scripts/clean_metadata.py
@@ -182,15 +182,33 @@ def main():
 
             # Generate unified diff
             # If dictionaries differ, generate JSON strings to show the diff
-            litellm_json = json.dumps(litellm_entry, indent=4, sort_keys=True).splitlines()
-            aider_json = json.dumps(aider_entry, indent=4, sort_keys=True).splitlines()
+            # Add a dummy key to ensure the *real* last key gets a comma
+            litellm_entry_copy = litellm_entry.copy()
+            aider_entry_copy = aider_entry.copy()
+            dummy_key = "zzzdummykey"
+            litellm_entry_copy[dummy_key] = True
+            aider_entry_copy[dummy_key] = True
+
+            litellm_json_lines = json.dumps(
+                litellm_entry_copy, indent=4, sort_keys=True
+            ).splitlines()
+            aider_json_lines = json.dumps(
+                aider_entry_copy, indent=4, sort_keys=True
+            ).splitlines()
+
+            # Remove the dummy key line before diffing
+            litellm_json_filtered = [
+                line for line in litellm_json_lines if dummy_key not in line
+            ]
+            aider_json_filtered = [line for line in aider_json_lines if dummy_key not in line]
+
             diff = difflib.unified_diff(
-                aider_json,
-                litellm_json,
+                aider_json_filtered,
+                litellm_json_filtered,
                 fromfile=f"{key} (aider)",
                 tofile=f"{key} (litellm)",
                 lineterm="",
-                n=max(len(litellm_json), len(aider_json)),  # Show all lines
+                n=max(len(litellm_json_filtered), len(aider_json_filtered)),  # Show all lines
             )
 
             # Print the diff, skipping the header lines generated by unified_diff