poetry: poetry 1.1.x causes SSLCertVerificationError when installing packages from private repo

I have a poetry project, configured with a private pypi repo, that used to work well, but after upgrading poetry to 1.1.x (tried 1.1.0 to 1.1.2), it causes error like

#16 26.50 Retrying HTTP request in 0.5 seconds.
#16 27.13 Retrying HTTP request in 1.0 seconds.
#16 28.25 Retrying HTTP request in 1.5 seconds.
#16 29.87 Retrying HTTP request in 2.0 seconds.
#16 32.00 Retrying HTTP request in 2.5 seconds.
#16 34.71 
#16 34.71   SSLError
#16 34.71 
#16 34.71   HTTPSConnectionPool(host='<PRIVATE-REPO-HOST>)', port=443): Max retries exceeded with url: <URL-to-myapp-0.1.3-py3-none-any.whl (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1124)')))
#16 34.71 
#16 34.71   at /usr/local/lib/python3.8/site-packages/requests/adapters.py:514 in send
#16 34.76       510│                 raise ProxyError(e, request=request)
#16 34.76       511│ 
#16 34.76       512│             if isinstance(e.reason, _SSLError):
#16 34.76       513│                 # This branch is for urllib3 v1.22 and later.
#16 34.76     → 514│                 raise SSLError(e, request=request)
#16 34.76       515│ 
#16 34.76       516│             raise ConnectionError(e, request=request)
#16 34.76       517│ 
#16 34.76       518│         except ClosedPoolError as e:
#16 34.76 
#16 ERROR: executor failed running [/bin/sh -c poetry install --no-dev]: runc did not terminate sucessfully

when downloading packages that are only available in the private repo.

When I downgrade poetry to 1.0.10, it then works fine.