diff --git a/shallow.c b/shallow.c
index 186e9178f3..d37d2bc179 100644
--- a/shallow.c
+++ b/shallow.c
@@ -198,6 +198,7 @@ struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
 		}
 	}
 	deep_clear_commit_depth(&depths, free_depth_in_slab);
+	object_array_clear(&stack);
 
 	return result;
 }