diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index f53c42380832..8c14f84a8770 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -46,6 +46,8 @@
 #    define SMPWMB      eieio
 #endif
 
+/* clang defines this macro for a builtin, which will not work with runtime patching */
+#undef __lwsync
 #define __lwsync()	__asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory")
 #define dma_rmb()	__lwsync()
 #define dma_wmb()	__asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory")