diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 29308e3..e912378 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -190,7 +190,7 @@
 	return res;
 }
 
-void put_ext4(uint64_t off, void *buf, uint32_t size)
+void put_ext4(uint64_t off, const void *buf, uint32_t size)
 {
 	uint64_t startblock;
 	uint64_t remainder;