diff --git a/javascript/ql/src/Security/CWE-178/CaseSensitiveMiddlewarePath.ql b/javascript/ql/src/Security/CWE-178/CaseSensitiveMiddlewarePath.ql
index 2045d801c702..997ee8971a5a 100644
--- a/javascript/ql/src/Security/CWE-178/CaseSensitiveMiddlewarePath.ql
+++ b/javascript/ql/src/Security/CWE-178/CaseSensitiveMiddlewarePath.ql
@@ -66,7 +66,7 @@ predicate isCaseSensitiveMiddleware(
     regexp.getAReference().flowsTo(arg) and
     exists(string flags |
       flags = regexp.tryGetFlags() and
-      not RegExp::isIgnoreCase(flags)
+      not RegExp::maybeIgnoreCase(flags)
     )
   )
 }