# Tls1.1 to 1.2

**URL:** <https://discourse.mitmproxy.org/t/tls1-1-to-1-2/1624>\
**Category:** help\
**Created:** [August 1, 2019, 2:53pm UTC](https://discourse.mitmproxy.org/t/tls1-1-to-1-2/1624 "2019-08-01T14:53:04Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![bibi](https://avatars.discourse-cdn.com/v4/letter/b/3e96dc/32.png) [@bibi](https://discourse.mitmproxy.org/u/bibi)\
**Post date:** [August 1, 2019, 2:53pm UTC](https://discourse.mitmproxy.org/t/tls1-1-to-1-2/1624/1 "2019-08-01T14:53:04Z")

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Hello,

I have an app who only talks on tls 1.1 and since few days, requested server now only talk on tls v1.2

I am using mitmproxy docker image, but it’s not working, and I am getting this error

Cannot establish TLS with website:443 (sni: website): TlsException(“SSL handshake error: Error([(‘SSL routines’, ‘ssl3\_read\_bytes’, ‘sslv3 alert handshake failure’)],)”,)

How can I force proxy to use tls 1.2 ?  
I have try to set ssl\_version\_server: TLSv1\_2 but same issue

I have found the same problem : [Try to run old app with TLSv1.0 only against TLSv1.1+ only server](https://discourse.mitmproxy.org/t/try-to-run-old-app-with-tlsv1-0-only-against-tlsv1-1-only-server/903)

but no solution in the topic :’(

Thx for your help