The Fix
pip install celery==5.5.3
Based on closed celery/celery issue #9680 · PR/commit linked
Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.
@@ -1 +1 @@
@@ -1 +1 @@
-pymongo==4.10.1
+kombu[mongodb]
diff --git a/requirements/extras/msgpack.txt b/requirements/extras/msgpack.txt
pip install celery[redis]
...
Successfully installed PyJWT-2.9.0 amqp-5.3.1 billiard-4.2.1 celery-5.5.2 click-8.1.8
click-didyoumean-0.3.1 click-plugins-1.1.1 click-repl-0.3.0 kombu-5.5.3
prompt-toolkit-3.0.51 python-dateutil-2.9.0.post0 redis-5.3.0 six-1.17.0
tzdata-2025.2 vine-5.1.0 wcwidth-0.2.13
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
Option A — Upgrade to fixed release\npip install celery==5.5.3\nWhen NOT to use: Do not use if it changes public behavior or if the failure cannot be reproduced.\n\n
Why This Fix Works in Production
- Trigger: Celery does not respect the redis-py version bounds specified by kombu (redis-py 5.3.0 was released)
- Mechanism: Limits the redis version to <=5.2.1 to match Kombu's specifications, addressing the issue where Celery installs redis 5.3.0 despite Kombu not supporting it.
- Why the fix works: Limits the redis version to <=5.2.1 to match Kombu's specifications, addressing the issue where Celery installs redis 5.3.0 despite Kombu not supporting it. (first fixed release: 5.5.3).
- If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.
Why This Breaks in Prod
- Production symptom (often without a traceback): Celery does not respect the redis-py version bounds specified by kombu (redis-py 5.3.0 was released)
Proof / Evidence
- GitHub issue: #9680
- Fix PR: https://github.com/celery/celery/pull/9696
- First fixed release: 5.5.3
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.64
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“I have some time, i am goin to come with a draft PR https://github.com/celery/celery/pull/9696”
“This goes for other extra dependencies as well I suppose.”
“> This goes for other extra dependencies as well I suppose”
“@woutdenolf > > This goes for other extra dependencies as well I suppose”
Failure Signature (Search String)
- Celery does not respect the redis-py version bounds specified by kombu (redis-py 5.3.0 was released)
- So kombu does not support 5.3.0 yet.
Copy-friendly signature
Failure Signature
-----------------
Celery does not respect the redis-py version bounds specified by kombu (redis-py 5.3.0 was released)
So kombu does not support 5.3.0 yet.
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Celery does not respect the redis-py version bounds specified by kombu (redis-py 5.3.0 was released)
So kombu does not support 5.3.0 yet.
Minimal Reproduction
pip install celery[redis]
...
Successfully installed PyJWT-2.9.0 amqp-5.3.1 billiard-4.2.1 celery-5.5.2 click-8.1.8
click-didyoumean-0.3.1 click-plugins-1.1.1 click-repl-0.3.0 kombu-5.5.3
prompt-toolkit-3.0.51 python-dateutil-2.9.0.post0 redis-5.3.0 six-1.17.0
tzdata-2025.2 vine-5.1.0 wcwidth-0.2.13
What Broke
Users experience compatibility issues due to incorrect redis version installation.
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install celery==5.5.3
Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.
Fix reference: https://github.com/celery/celery/pull/9696
First fixed release: 5.5.3
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- Do not use if it changes public behavior or if the failure cannot be reproduced.
Verify Fix
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
Did This Fix Work in Your Case?
Quick signal helps us prioritize which fixes to verify and improve.
Prevention
- Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
- Pin production dependencies and upgrade only with a reproducible test that hits the failing path.
Version Compatibility Table
| Version | Status |
|---|---|
| 5.5.3 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.