diff --git a/lib/clang/clang.build.mk b/lib/clang/clang.build.mk
index 0d3151178eb9..fb64b16935f2 100644
--- a/lib/clang/clang.build.mk
+++ b/lib/clang/clang.build.mk
@@ -1,16 +1,18 @@
 # $FreeBSD$
 
 .include <src.opts.mk>
 
 .ifndef CLANG_SRCS
 .error Please define CLANG_SRCS before including this file
 .endif
 
 CFLAGS+=	-I${CLANG_SRCS}/include
 
 .if ${MK_CLANG_FULL} != "no"
 CFLAGS+=	-DCLANG_ENABLE_ARCMT
 CFLAGS+=	-DCLANG_ENABLE_STATIC_ANALYZER
 .endif
 
+CFLAGS.gcc+=	-fno-strict-aliasing
+
 .include "llvm.build.mk"