diff --git a/.github/workflows/runtests.yml b/.github/workflows/runtests.yml
index b36e2410..5ae97069 100644
--- a/.github/workflows/runtests.yml
+++ b/.github/workflows/runtests.yml
@@ -92,18 +92,18 @@ jobs:
     strategy:
       matrix:
         julia-version:
-          - '1.6'
+          - '1.10'
           - 'nightly'
-        os: ['macos-latest']
+        os: [ 'macos-14' ] # aarch64
         include:
-          - os: 'macos-14'
-            julia-version: '1.10'
+          - os: 'macos-13' # x86_64
+            julia-version: '1.6'
       fail-fast: false
 
     steps:
       - uses: actions/checkout@v4
       - name: "Set up Julia"
-        uses: julia-actions/setup-julia@v1
+        uses: julia-actions/setup-julia@v1.9.6
         with:
           version: ${{ matrix.julia-version }}
       - uses: julia-actions/cache@v1
diff --git a/OscarCI.toml b/OscarCI.toml
index 98c93045..67c2040d 100644
--- a/OscarCI.toml
+++ b/OscarCI.toml
@@ -26,8 +26,8 @@ julia-version = [ "~1.6.0-0", "~1.10.0-0"]
   julia-version = "1.6"
   os = "macos-latest"
 
-  [include.macaarch64]
+  [include.macamd64]
   Oscar = "<matching>"
   Polymake = ""
   julia-version = "1.10"
-  os = "macos-14"
+  os = "macos-13"