--- Makefile	(revision 487356)
+++ Makefile	(working copy)
@@ -15,7 +15,7 @@ 
 
 EXTRA_PATCHES=	${FILESDIR}/php_zts.patch:-p1
 
-USES+=		cpe
+USES+=		compiler:c11 cpe
 
 CPE_VENDOR=	nginx
 CPE_PRODUCT=	unit