diff --git modules/file/file.js modules/file/file.js
index e6661cc..c6027dd 100644
--- modules/file/file.js
+++ modules/file/file.js
@@ -65,7 +65,7 @@ Drupal.file = Drupal.file || {
     if (accept.length > 1 && this.value.length > 0) {
       var acceptableMatch = new RegExp('\\.(' + accept + ')$', 'gi');
       if (!acceptableMatch.test(this.value)) {
-        var error = Drupal.t("The selected file %filename cannot not be uploaded. Only files with the following extensions are allowed: %extensions.", {
+        var error = Drupal.t("The selected file %filename cannot be uploaded. Only files with the following extensions are allowed: %extensions.", {
           '%filename': this.value,
           '%extensions': accept.replace(/\|/g, ', ')
         });