diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 96f7e8523ee8498ea63673f074cfd0389a2c440d..42d5cb0f503fb825104d7a0f02f79b63ab6f63da 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -124,7 +124,7 @@ bool regmap_precious(struct regmap *map, unsigned int reg)
 }
 
 static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
-	unsigned int num)
+	size_t num)
 {
 	unsigned int i;