diff --git a/7_more_join_operations.sql b/7_more_join_operations.sql
index 15d5953..faed682 100644
--- a/7_more_join_operations.sql
+++ b/7_more_join_operations.sql
@@ -126,7 +126,7 @@ FROM movie
 JOIN casting
 ON movie.id = casting.movieid
 WHERE movie.yr = 1978
-GROUP BY movie.id
+GROUP BY movie.title
 ORDER BY COUNT(*) DESC
 
 -- # 16. List all the people who have worked with 'Art Garfunkel'.
@@ -143,4 +143,4 @@ SELECT a.name
           JOIN casting
             ON casting.actorid = actor.id
          WHERE actor.name != 'Art Garfunkel') as a
-    ON m.id = a.movieid;
\ No newline at end of file
+    ON m.id = a.movieid;