diff --git a/riotfile.py b/riotfile.py
index c3f806a6697..acbb4452654 100644
--- a/riotfile.py
+++ b/riotfile.py
@@ -358,7 +358,9 @@ def select_pys(min_version=MIN_PYTHON_VERSION, max_version=MAX_PYTHON_VERSION):
                     },
                     pkgs={
                         "celery": [
-                            "~=5.0.5",
+                            # Pin until https://github.com/celery/celery/issues/6829 is resolved.
+                            # "~=5.0.5",
+                            "==5.0.5",
                             "~=5.0",  # most recent 5.x
                             latest,
                         ],