diff --git a/arch/common/common-defs.h b/arch/common/common-defs.h
index 0dbb89c..9ac11dc 100644
--- a/arch/common/common-defs.h
+++ b/arch/common/common-defs.h
@@ -33,4 +33,6 @@ __proc:							\
 	.weak	__alias;				\
 	__alias = __real;
 
+#define REG_OFFSET(__reg)       (MCONTEXT_GREGS + ((__reg) * SZ_REG))
+
 #endif