diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
index e3cd4f0..160879c 100644
--- a/ssl/s3_enc.c
+++ b/ssl/s3_enc.c
@@ -779,7 +779,8 @@ int n_ssl3_mac(SSL *ssl, unsigned char *md, int send)
 		/* Chop the digest off the end :-) */
 		EVP_MD_CTX_init(&md_ctx);
 
-		EVP_MD_CTX_copy_ex( &md_ctx,hash);
+		if (!EVP_MD_CTX_copy_ex( &md_ctx,hash))
+			return -1;
 		EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
 		EVP_DigestUpdate(&md_ctx,ssl3_pad_1,npad);
 		EVP_DigestUpdate(&md_ctx,seq,8);
@@ -791,7 +792,8 @@ int n_ssl3_mac(SSL *ssl, unsigned char *md, int send)
 		EVP_DigestUpdate(&md_ctx,rec->input,rec->length);
 		EVP_DigestFinal_ex( &md_ctx,md,NULL);
 
-		EVP_MD_CTX_copy_ex( &md_ctx,hash);
+		if (!EVP_MD_CTX_copy_ex( &md_ctx,hash))
+			return -1;
 		EVP_DigestUpdate(&md_ctx,mac_sec,md_size);
 		EVP_DigestUpdate(&md_ctx,ssl3_pad_2,npad);
 		EVP_DigestUpdate(&md_ctx,md,md_size);