diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index e974d69d7..671fb9bb6 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -591,6 +591,11 @@ class RemoteFilesystem
         } elseif ($this->config && in_array($this->originUrl, $this->config->get('gitlab-domains'), true)) {
             $message = "\n".'Could not fetch '.$this->fileUrl.', enter your ' . $this->originUrl . ' credentials ' .($httpStatus === 401 ? 'to access private repos' : 'to go over the API rate limit');
             $gitLabUtil = new GitLab($this->io, $this->config, null);
+
+            if ($this->io->hasAuthentication($this->originUrl) && ($auth = $this->io->getAuthentication($this->originUrl)) && $auth['password'] === 'private-token') {
+                throw new TransportException("Invalid credentials for '" . $this->fileUrl . "', aborting.", $httpStatus);
+            }
+
             if (!$gitLabUtil->authorizeOAuth($this->originUrl)
                 && (!$this->io->isInteractive() || !$gitLabUtil->authorizeOAuthInteractively($this->scheme, $this->originUrl, $message))
             ) {