diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c
index dbea6020ffe7..575292a33bdf 100644
--- a/arch/x86/crypto/cast5_avx_glue.c
+++ b/arch/x86/crypto/cast5_avx_glue.c
@@ -66,8 +66,6 @@ static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
 	void (*fn)(struct cast5_ctx *ctx, u8 *dst, const u8 *src);
 	int err;
 
-	fn = (enc) ? cast5_ecb_enc_16way : cast5_ecb_dec_16way;
-
 	err = blkcipher_walk_virt(desc, walk);
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
@@ -79,6 +77,7 @@ static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
 
 		/* Process multi-block batch */
 		if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
+			fn = (enc) ? cast5_ecb_enc_16way : cast5_ecb_dec_16way;
 			do {
 				fn(ctx, wdst, wsrc);