diff --git a/crypto/ecdh/ech_kdf.c b/crypto/ecdh/ech_kdf.c
index 84bf108b9..848b91745 100644
--- a/crypto/ecdh/ech_kdf.c
+++ b/crypto/ecdh/ech_kdf.c
@@ -90,7 +90,7 @@ int ECDH_KDF_X9_62(unsigned char *out, size_t outlen,
 			goto err;
 		if (!EVP_DigestUpdate(&mctx, sinfo, sinfolen))
 			goto err;
-		if (outlen > mdlen)
+		if (outlen >= mdlen)
 			{
 			if (!EVP_DigestFinal(&mctx, out, NULL))
 				goto err;