# oso-oso gem fails on M1 Mac: have x86_64, need arm64e (fixed in 0.26.2)
## What was going on
The oso-oso Ruby gem failed to load on an M1 MacBook Pro with LoadError: Could not open library '.../libpolar.dylib': dlopen(...): tried ... have 'x86_64', need 'arm64e'. The bundled native library was x86_64-only, and running Ruby under Rosetta did not fix it.
## The fix that worked
M1 (arm64) support for the Ruby gem landed in oso 0.26.2; upgrade the oso-oso gem to 0.26.2 or newer. Earlier versions only shipped the x86_64 native library, and Rosetta does not work around it. The changelog entry for 0.26.2 explicitly lists M1/Ruby arm64 support.
## Where this came from
https://github.com/osohq/oso/issues/1525