diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index d1e3def..d6c3431 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -10,8 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1'
-          - 'nightly'
+          - '1.6'
         os:
           - ubuntu-latest
           - macOS-latest