diff --git a/src/jquery.autocomplete.js b/src/jquery.autocomplete.js
index b99146c..ed922f8 100644
--- a/src/jquery.autocomplete.js
+++ b/src/jquery.autocomplete.js
@@ -819,7 +819,7 @@
             // Cache results if cache is not disabled:
             if (!options.noCache) {
                 that.cachedResponse[cacheKey] = result;
-                if (options.preventBadQueries && !result.suggestions.length) {
+                if (options.preventBadQueries && !result.suggestions.length && originalQuery) {
                     that.badQueries.push(originalQuery);
                 }
             }