diff --git a/tests/scripts/docs_check_outputs.sh b/tests/scripts/docs_check_outputs.sh
index 0ae2574..06f9da1 100644
--- a/tests/scripts/docs_check_outputs.sh
+++ b/tests/scripts/docs_check_outputs.sh
@@ -12,6 +12,7 @@ printf '%s\n' "$files" | while IFS= read -r f; do
     [ -z "$f" ] && continue
     if [ ! -f "$f" ]; then
         echo "$f" >> "$missing_file"
+        missing=$((missing + 1))
     fi
 done