diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f35efcc..5a348b6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
       fail-fast: false
       matrix:
         machine:
-          - version: 'nightly'
+          - version: '1.6'
             os: ubuntu-latest
             arch: x64
           - version: '1'