diff --git a/package/kernel/lantiq/ltq-deu/src/ifxmips_aes.c b/package/kernel/lantiq/ltq-deu/src/ifxmips_aes.c
index 4139b343da..2bb2726be6 100644
--- a/package/kernel/lantiq/ltq-deu/src/ifxmips_aes.c
+++ b/package/kernel/lantiq/ltq-deu/src/ifxmips_aes.c
@@ -1798,7 +1798,7 @@ static int gcm_aes_decrypt(struct aead_request *req)
 
     //crypt and hash
     while ((nbytes = dec_bytes = walk.nbytes) && (walk.nbytes >= AES_BLOCK_SIZE)) {
-        u8 *temp;
+        const u8 *temp;
         dec_bytes -= (nbytes % AES_BLOCK_SIZE);
         temp = walk.src.virt.addr;
         while (dec_bytes) {