diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
index c8006607f947..136cdcdf92ef 100644
--- a/include/linux/kmemcheck.h
+++ b/include/linux/kmemcheck.h
@@ -145,10 +145,12 @@ static inline bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size)
 
 #define kmemcheck_annotate_bitfield(ptr, name)				\
 	do {								\
+		int _n;							\
+									\
 		if (!ptr)						\
 			break;						\
 									\
-		int _n = (long) &((ptr)->name##_end)			\
+		_n = (long) &((ptr)->name##_end)			\
 			- (long) &((ptr)->name##_begin);		\
 		BUILD_BUG_ON(_n < 0);					\
 									\