diff --git a/common_alpha.h b/common_alpha.h
index 9739c941d..f1ea8ff94 100644
--- a/common_alpha.h
+++ b/common_alpha.h
@@ -43,6 +43,7 @@
 
 #define MB  asm("mb")
 #define WMB asm("wmb")
+#define RMB asm("rmb")
 
 static void __inline blas_lock(unsigned long *address){
 #ifndef __DECC