diff --git a/src/org/mozilla/javascript/commonjs/module/provider/UrlModuleSourceProvider.java b/src/org/mozilla/javascript/commonjs/module/provider/UrlModuleSourceProvider.java
index 7ada3f8bc9..46aefb85f5 100644
--- a/src/org/mozilla/javascript/commonjs/module/provider/UrlModuleSourceProvider.java
+++ b/src/org/mozilla/javascript/commonjs/module/provider/UrlModuleSourceProvider.java
@@ -249,7 +249,7 @@ boolean updateValidator(
         private boolean isResourceChanged(URLConnection urlConnection) throws IOException {
             if (urlConnection instanceof HttpURLConnection) {
                 return ((HttpURLConnection) urlConnection).getResponseCode()
-                        == HttpURLConnection.HTTP_NOT_MODIFIED;
+                        != HttpURLConnection.HTTP_NOT_MODIFIED;
             }
             return lastModified != urlConnection.getLastModified();
         }