diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e38dd7d..b26a395 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -138,8 +138,8 @@
 	return cpu_to_le32(csum);
 }
 
-int ext4_superblock_csum_verify(struct super_block *sb,
-				struct ext4_super_block *es)
+static int ext4_superblock_csum_verify(struct super_block *sb,
+				       struct ext4_super_block *es)
 {
 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))