diff --git a/.github/workflows/example-plots.yml b/.github/workflows/example-plots.yml
index 6700ae5..9ccbab0 100644
--- a/.github/workflows/example-plots.yml
+++ b/.github/workflows/example-plots.yml
@@ -10,7 +10,7 @@ jobs:
       max-parallel: 8
       matrix:
         python-version: [3.7, 3.8]
-        os: [macos-latest, windows-latest, ubuntu-latest]
+        os: [macos-13, windows-latest, ubuntu-latest]
 
     steps:
     - uses: actions/checkout@v4
diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index 380f4f7..2ac3635 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -10,7 +10,7 @@ jobs:
       max-parallel: 8
       matrix:
         python-version: [3.7, 3.8]
-        os: [macos-latest, windows-latest, ubuntu-latest]
+        os: [macos-13, windows-latest, ubuntu-latest]
 
     steps:
     - uses: actions/checkout@v4