diff --git a/src/mednet/scripts/upload.py b/src/mednet/scripts/upload.py
index 8b94459754529398b8bd71682f722c550ab3eb11..c8c7f8da1284095f37a37049ee8ccec317057c5a 100644
--- a/src/mednet/scripts/upload.py
+++ b/src/mednet/scripts/upload.py
@@ -32,6 +32,14 @@ def _get_gitlab_config():
         token = input(f"{server} (user or project) token: ")
         gl = gitlab.Gitlab(server, private_token=token, api_version="4")
         config = {"idiap": {"private_token": token}}
+    # try to authenticate with given credential.
+    try:
+        gl.auth()
+    except:
+        logger.error("Gitlab credential issue, authentication failed.")
+        raise RuntimeError(
+            f"There is a Gitlab credential issue that must be fixed before uploading."
+        )
 
     return gl, config