diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 4621554..d458dec 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -18,7 +18,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ ubuntu-18.04, windows-latest, macos-latest ]
+        os: [ ubuntu-18.04, windows-latest, macos-10.15 ]
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
@@ -32,9 +32,6 @@ jobs:
         with:
           python-version: 3.9.7
 
-      - uses: kenchan0130/actions-system-info@master
-        id: system-info
-
       - name: Declare some variables
         id: vars
         shell: bash