diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 6fb0808e87c81af9c4ad840cde86b892f96ee8a3..bef2e36c01b4b9769227f45d4960e46aef234d31 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -601,7 +601,7 @@ do {									\
  */
 #define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
 
-static inline sector_t to_sector(unsigned long n)
+static inline sector_t to_sector(unsigned long long n)
 {
 	return (n >> SECTOR_SHIFT);
 }