Celery 'False' will be ignored in Celery kwargs config (Fix)

The Fix

pip install celery==5.2.0rc2

Based on closed celery/celery issue #6865 · PR/commit linked

Production note: This usually shows up under retries/timeouts. Treat it as a side-effect risk until you can verify behavior with a canary + real traffic.

Jump to Verify Open PR/Commit

@@ -323,7 +323,7 @@ def on_init(self):
 
     def __autoset(self, key, value):
-        if value:
+        if value is not None:
             self._preconf[key] = value

repro.py

from celery import Celery
app = Celery('tasks',
    broker='redis://localhost',
    broker_transport_options = {'visibility_timeout': 0},
    task_acks_late=True,
    task_acks_on_failure_or_timeout=False,
)
print(app.conf['task_acks_on_failure_or_timeout'])

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\npip install celery==5.2.0rc2\nWhen NOT to use: Do not use this fix if your application relies on the previous behavior of ignoring 'False' values.\n\n

Why This Fix Works in Production

Trigger: - [x] I have included all related issues and possible duplicate issues
Mechanism: 'False' values were ignored in Celery kwargs configuration due to improper filtering
Why the fix works: Allows using non-true values in Celery kwargs configuration, addressing the issue where 'False' would be ignored. (first fixed release: 5.2.0rc2).

Production impact:

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

'False' values were ignored in Celery kwargs configuration due to improper filtering
Production symptom (often without a traceback): - [x] I have included all related issues and possible duplicate issues

Proof / Evidence

GitHub issue: #6865
Fix PR: https://github.com/celery/celery/pull/6897
First fixed release: 5.2.0rc2
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.66

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“Hey @gundam78 :wave:, Thank you for opening an issue”

@open-collective-bot · 2021-07-20 · source

Failure Signature (Search String)

- [x] I have included all related issues and possible duplicate issues
or possible duplicates to this issue as requested by the checklist above.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
- [x] I have included all related issues and possible duplicate issues
or possible duplicates to this issue as requested by the checklist above.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
- [x] I have included all related issues and possible duplicate issues
or possible duplicates to this issue as requested by the checklist above.

Minimal Reproduction

repro.py

from celery import Celery
app = Celery('tasks',
    broker='redis://localhost',
    broker_transport_options = {'visibility_timeout': 0},
    task_acks_late=True,
    task_acks_on_failure_or_timeout=False,
)
print(app.conf['task_acks_on_failure_or_timeout'])

What Broke

Users experienced unexpected behavior when passing 'False' to Celery kwargs, leading to misconfigured tasks.

Why It Broke

'False' values were ignored in Celery kwargs configuration due to improper filtering

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

pip install celery==5.2.0rc2

When NOT to use: Do not use this fix if your application relies on the previous behavior of ignoring 'False' values.

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/6897

First fixed release: 5.2.0rc2

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

Do not use this fix if your application relies on the previous behavior of ignoring 'False' values.

Verify Fix

verify

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

Make timeouts explicit and test them (unit + integration) to avoid silent behavior changes.
Instrument retries (attempt count + reason) and alert on spikes to catch dependency slowdowns.

Version Compatibility Table

Version	Status
5.2.0rc2	Fixed

Related Issues

No related fixes found.

Cluster: celery:configuration-error Celery hub Celery best practices All hubs All clusters

Related clusters: Data consistency Duplicates Duplicate processing

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.