diff --git a/modules/openid/lib/Auth/Source/OpenIDConsumer.php b/modules/openid/lib/Auth/Source/OpenIDConsumer.php
index 67a73b26c6d2428fdd1cde8fe5a40ea8bf5aeb68..2144ad1b0006f675c63f163af341f0f66c804b12 100644
--- a/modules/openid/lib/Auth/Source/OpenIDConsumer.php
+++ b/modules/openid/lib/Auth/Source/OpenIDConsumer.php
@@ -5,6 +5,10 @@
  * used is PHP4-compatible, and not PHP5 strict-standards compatible.
  */
 SimpleSAML_Utilities::maskErrors(E_STRICT);
+if (defined('E_DEPRECATED')) {
+	/* PHP 5.3 also has E_DEPRECATED. */
+	SimpleSAML_Utilities::maskErrors(constant('E_DEPRECATED'));
+}
 
 /* Add the OpenID library search path. */
 set_include_path(get_include_path() . PATH_SEPARATOR . dirname(dirname(dirname(dirname(dirname(dirname(__FILE__)))))) . '/lib');