diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 66ee3bbc9872..d084de4c60f2 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -4026,7 +4026,7 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
 		pr_err("alg: akcipher: %s test failed. err %d\n", op, err);
 		goto free_all;
 	}
-	if (!vecs->siggen_sigver_test) {
+	if (!vecs->siggen_sigver_test && c) {
 		if (req->dst_len != c_size) {
 			pr_err("alg: akcipher: %s test failed. Invalid output len\n",
 			       op);
@@ -4057,6 +4057,11 @@ static int test_akcipher_one(struct crypto_akcipher *tfm,
 		goto free_all;
 	}
 
+	if (!vecs->siggen_sigver_test && !c) {
+		c = outbuf_enc;
+		c_size = req->dst_len;
+	}
+
 	op = vecs->siggen_sigver_test ? "sign" : "decrypt";
 	if (WARN_ON(c_size > PAGE_SIZE))
 		goto free_all;