diff --git a/core/modules/comment/comment.install b/core/modules/comment/comment.install
index e285291..3d093fb 100644
--- a/core/modules/comment/comment.install
+++ b/core/modules/comment/comment.install
@@ -705,7 +705,7 @@ function comment_update_8008(&$sandbox) {
  * Remove the comment_block_count variable.
  */
 function comment_update_8009() {
-  variable_del('comment_block_count');
+  update_variable_del('comment_block_count');
 }
 
 /**