diff --git a/modules/file/file.js b/modules/file/file.js
index 1071384..f397057 100644
--- a/modules/file/file.js
+++ b/modules/file/file.js
@@ -66,20 +66,23 @@ Drupal.file = Drupal.file || {
    */
   validateExtension: function (event) {
     // Remove any previous errors.
-    $('.file-upload-js-error').remove();
+    if (this.value)
+    {
+      $('.file-upload-js-error').remove();
 
-    // Add client side validation for the input[type=file].
-    var extensionPattern = event.data.extensions.replace(/,\s*/g, '|');
-    if (extensionPattern.length > 1 && this.value.length > 0) {
-      var acceptableMatch = new RegExp('\\.(' + extensionPattern + ')$', 'gi');
-      if (!acceptableMatch.test(this.value)) {
-        var error = Drupal.t("The selected file %filename cannot be uploaded. Only files with the following extensions are allowed: %extensions.", {
-          '%filename': this.value,
-          '%extensions': extensionPattern.replace(/\|/g, ', ')
-        });
-        $(this).parents('div.form-managed-file').prepend('<div class="messages error file-upload-js-error">' + error + '</div>');
-        this.value = '';
-        return false;
+      // Add client side validation for the input[type=file].
+      var extensionPattern = event.data.extensions.replace(/,\s*/g, '|');
+      if (extensionPattern.length > 1 && this.value.length > 0) {
+        var acceptableMatch = new RegExp('\\.(' + extensionPattern + ')$', 'gi');
+        if (!acceptableMatch.test(this.value)) {
+          var error = Drupal.t("The selected file %filename cannot be uploaded. Only files with the following extensions are allowed: %extensions.", {
+            '%filename': this.value,
+            '%extensions': extensionPattern.replace(/\|/g, ', ')
+          });
+          $(this).parents('div.form-managed-file').prepend('<div class="messages error file-upload-js-error">' + error + '</div>');
+          this.value = '';
+          return false;
+        }
       }
     }
   },