diff --git a/.github/workflows/ci_test-slow.yml b/.github/workflows/ci_test-slow.yml
index 38b5a743dc..c3e1a41ae5 100644
--- a/.github/workflows/ci_test-slow.yml
+++ b/.github/workflows/ci_test-slow.yml
@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macOS-latest]
+        os: [ubuntu-20.04, windows-2019, macOS-10.15]
         # same config as '.azure-pipelines/gpu-tests.yml'
         python-version: ["3.7"]
         pytorch-version: ["1.8"]