diff --git a/cloze.module b/cloze.module
index 55fc4d4..e4ab064 100644
--- a/cloze.module
+++ b/cloze.module
@@ -103,14 +103,14 @@ function _cloze_get_question_chunks($question) {
     $pos = strpos($question, '[');
     if ($pos) {
       $substring = substr($question, 0, $pos);
-      $question = preg_replace('/'. preg_quote($substring) .'/', '', $question, 1);
+      $question = preg_replace('/'. preg_quote($substring, '/') .'/', '', $question, 1);
       $chunks[] = $substring;
       $match = TRUE;
     }
     $pos = strpos($question, ']');
     if ($pos !== FALSE) {
       $substring = substr($question, 0, $pos + 1);
-      $question = preg_replace('/'. preg_quote($substring) .'/', '', $question, 1);
+      $question = preg_replace('/'. preg_quote($substring, '/') .'/', '', $question, 1);
       $chunks[] = $substring;
       $match = TRUE;
     }