diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index f310f2ba8bad9..ec746cc4b1f81 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2582,7 +2582,7 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string
 
 static int get_key_size(char **key_string)
 {
-	return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
+	return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
 }
 
 #endif /* CONFIG_KEYS */