diff --git a/extlib/OAuth.php b/extlib/OAuth.php
index 60c50f1cea..495121374e 100644
--- a/extlib/OAuth.php
+++ b/extlib/OAuth.php
@@ -3,7 +3,7 @@
 
 /* Generic exception class
  */
-if (!class_exists(OAuthException)) {
+if (!class_exists('OAuthException')) {
   class OAuthException extends Exception {
     // pass
   }