Index: trunk/optimizer.c
===================================================================
--- trunk/optimizer.c	(revision 845)
+++ trunk/optimizer.c	(revision 847)
@@ -105,5 +105,8 @@
 				case ZEND_SWITCH_FREE:
 				case ZEND_FREE:
-					if (!(brk_opline->extended_value & EXT_TYPE_FREE_ON_RETURN)) {
+#ifdef EXT_TYPE_FREE_ON_RETURN
+					if (!(brk_opline->extended_value & EXT_TYPE_FREE_ON_RETURN))
+#endif
+					{
 						can_convert = 0;
 					}