diff --git a/src/lib-smtp/smtp-server-connection.c b/src/lib-smtp/smtp-server-connection.c
index 56b7c2b10e..eeeecddb1e 100644
--- a/src/lib-smtp/smtp-server-connection.c
+++ b/src/lib-smtp/smtp-server-connection.c
@@ -689,7 +689,8 @@ int smtp_server_connection_flush(struct smtp_server_connection *conn)
 
 	if ((ret = o_stream_flush(output)) <= 0) {
 		if (ret < 0) {
-			if (errno != EPIPE && errno != ECONNRESET) {
+			if (output->stream_errno != EPIPE &&
+			    output->stream_errno != ECONNRESET) {
 				smtp_server_connection_error(conn,
 					"Connection lost: write(%s) failed: %s",
 					o_stream_get_name(output),
diff --git a/src/lib-smtp/smtp-server-reply.c b/src/lib-smtp/smtp-server-reply.c
index 6c034f3207..0663ecdf9f 100644
--- a/src/lib-smtp/smtp-server-reply.c
+++ b/src/lib-smtp/smtp-server-reply.c
@@ -425,7 +425,8 @@ static int smtp_server_reply_send_real(struct smtp_server_reply *reply,
 	}
 
 	if (o_stream_send(output, str_data(textbuf), str_len(textbuf)) < 0) {
-		if (errno != EPIPE && errno != ECONNRESET) {
+		if (output->stream_errno != EPIPE &&
+		    output->stream_errno != ECONNRESET) {
 			*error_r = t_strdup_printf("write(%s) failed: %s",
 						   o_stream_get_name(output),
 						   o_stream_get_error(output));