diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 3aac8c1..a8eef6d 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -17,19 +17,12 @@ jobs:
     strategy:
       matrix:
         version:
-          - '1.6'
           - '1.9'
-          - 'nightly'
         os:
-          - macOS-latest
-          - windows-latest
           - ubuntu-latest
         arch:
           - x64
           - x86
-        exclude:
-          - os: macOS-latest
-            arch: x86
     steps:
       - uses: actions/checkout@v2
       - uses: julia-actions/setup-julia@v1