diff --git a/arch/sh/include/asm/uaccess_64.h b/arch/sh/include/asm/uaccess_64.h
index c01376c76b868..ca5073dd45967 100644
--- a/arch/sh/include/asm/uaccess_64.h
+++ b/arch/sh/include/asm/uaccess_64.h
@@ -24,6 +24,7 @@
 #define __get_user_size(x,ptr,size,retval)			\
 do {								\
 	retval = 0;						\
+	x = 0;							\
 	switch (size) {						\
 	case 1:							\
 		retval = __get_user_asm_b((void *)&x,		\