The Fix
pip install urllib3==1.26.13
Based on closed urllib3/urllib3 issue #2781 · 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%.
@@ -1,7 +1,7 @@
=========
.. warning::
- DEPRECATED: This module is deprecated and will be removed in a future 2.x release.
+ DEPRECATED: This module is deprecated and will be removed in urllib3 v2.1.0.
Read more in this `issue <https://github.com/urllib3/urllib3/issues/2680>`_.
Option A — Upgrade to fixed release\npip install urllib3==1.26.13\nWhen NOT to use: This fix is inappropriate if the deprecation timeline needs to remain vague for any reason.\n\n
Why This Fix Works in Production
- Trigger: Change deprecation warnings from "in a future version" to "in v2.1.0"
- Mechanism: Deprecation warnings lacked specificity about removal timelines, causing user confusion
- Why the fix works: Changes deprecation warnings to explicitly mention that deprecated features will be removed in urllib3 v2.1.0. (first fixed release: 1.26.13).
- 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
- Deprecation warnings lacked specificity about removal timelines, causing user confusion
- Production symptom (often without a traceback): Change deprecation warnings from "in a future version" to "in v2.1.0"
Proof / Evidence
- GitHub issue: #2781
- Fix PR: https://github.com/urllib3/urllib3/pull/2793
- First fixed release: 1.26.13
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.95
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.74
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“For extra visibility, consider documenting these on a single page, like: * https://docs.pytest.org/en/7.2.x/deprecations.html#deprecations * https://pillow.readthedocs.io/en/stable/deprecations.html I find these useful both as a user and a…”
“Thanks for the suggestion @hugovk! I like the long form rationale.”
Failure Signature (Search String)
- Change deprecation warnings from "in a future version" to "in v2.1.0"
Copy-friendly signature
Failure Signature
-----------------
Change deprecation warnings from "in a future version" to "in v2.1.0"
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Change deprecation warnings from "in a future version" to "in v2.1.0"
What Broke
Users may continue using deprecated features without urgency, risking future compatibility issues.
Why It Broke
Deprecation warnings lacked specificity about removal timelines, causing user confusion
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install urllib3==1.26.13
Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.
Fix reference: https://github.com/urllib3/urllib3/pull/2793
First fixed release: 1.26.13
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix is inappropriate if the deprecation timeline needs to remain vague for any reason.
Did This Fix Work in Your Case?
Quick signal helps us prioritize which fixes to verify and improve.
Prevention
- Add a CI check that diffs key outputs after upgrades (OpenAPI schema snapshots, JSON payload shapes, CLI output).
- Upgrade behind a canary and run integration tests against the canary before 100% rollout.
Version Compatibility Table
| Version | Status |
|---|---|
| 1.26.13 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.