diff --git a/src/base_facebook.php b/src/base_facebook.php
index 02a75dc..a6e6362 100755
--- a/src/base_facebook.php
+++ b/src/base_facebook.php
@@ -123,10 +123,10 @@ abstract class BaseFacebook
    * Default options for curl.
    */
   public static $CURL_OPTS = array(
-    CURLOPT_CONNECTTIMEOUT => 10,
-    CURLOPT_RETURNTRANSFER => true,
-    CURLOPT_TIMEOUT        => 60,
-    CURLOPT_USERAGENT      => 'facebook-php-3.0',
+    'CURLOPT_CONNECTTIMEOUT' => 10,
+    'CURLOPT_RETURNTRANSFER' => true,
+    'CURLOPT_TIMEOUT'        => 60,
+    'CURLOPT_USERAGENT'      => 'facebook-php-3.0',
   );
 
   /**