Fixed (verified)Last checked Oct 17, 2026LangChain#setup #regression

Import fails with 'No module named tenacity.asyncio'

Importing LangChain fails after the tenacity dependency is upgraded to 8.4.0.

From GitHub

Difficulty: Easy
Time: ~5 min
Steps: 2
Fixed in: langchain==0.2.6
Last checked: Oct 17, 2026

Verified fix: PR #22973 merged on 2024-06-18. Fixed in langchain==0.2.6 (first release published after the merge). Last checked 2026-10-17.

Symptom

Importing LangChain fails after the tenacity dependency is upgraded to 8.4.0.

Evidence what you'll see

ModuleNotFoundError: No module named 'tenacity.asyncio'
Only with tenacity 8.4.0 installed

Cause

tenacity 8.4.0 shipped broken, and LangChain's dependency range allowed it.

Fix steps

0 of 2 done

Step 1Upgrade LangChain to a release that includes PR #22973, which excludes tenacity 8.4.0.
Step 2Or pin tenacity to a version other than 8.4.0 in your own requirements.

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Verify the fix worked

Run python -c "import tenacity" and then import LangChain; both succeed.

Sources and credit

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