diff --git a/main.sh b/main.sh
index 69a1829..6ea16ba 100755
--- a/main.sh
+++ b/main.sh
@@ -140,4 +140,11 @@ find pinoutstmp -type d -empty -delete
 # This will get everything that didn't have a directory or title specified.
 [ -d pinoutstmp ] && cp -r pinoutstmp/* pinouts/ && rm -r pinoutstmp
 
+find pinouts/ -type f -name 'index.html' -print0 | while IFS= read -r -d '' f; do
+  DUPES=$(grep "cid\": " "$f" | uniq -d | tr -d '\n')
+  if [ -n "$DUPES" ]; then
+    if ! handle_warning "$WARNING_DUPE" "WARNING: Duplicate cids in $f: $DUPES"; then continue; fi
+  fi
+done
+
 echo "Completed processing $(echo -n "$CONNECTORS" | wc -l) mappings"