diff --git a/web/reviewer.js b/web/reviewer.js
index 57417fb4e..a225d8c61 100644
--- a/web/reviewer.js
+++ b/web/reviewer.js
@@ -86,5 +86,5 @@ function _clozeIsInsideMathjax(node) {
         return;
     }
     // look for mathjax opening in previous text
-    return /\(|\$\$/.test(node.previousSibling.textContent);
+    return /\\\(|\$\$/.test(node.previousSibling.textContent);
 }
\ No newline at end of file