diff --git a/lib/connect.c b/lib/connect.c
index b8fde5580d..11e6b888b7 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -1038,7 +1038,8 @@ CURLcode Curl_is_connected(struct Curl_easy *data,
     else
       hostname = conn->host.name;
 
-    failf(data, "Failed to connect to %s port %u after %ld ms: %s",
+    failf(data, "Failed to connect to %s port %u after "
+                "%" CURL_FORMAT_TIMEDIFF_T " ms: %s",
         hostname, conn->port,
         Curl_timediff(now, data->progress.t_startsingle),
         Curl_strerror(error, buffer, sizeof(buffer)));