diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
index bfd26c58d5e..e061377fbc7 100644
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -23,7 +23,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [ '3.8', '3.9', '3.10', '3.11', '3.12' ]
+        python-version: [ '3.12' ]
 
     uses: ./.github/workflows/build-wheels.yml
     with:
@@ -34,7 +34,7 @@ jobs:
       fail-fast: false
       matrix:
         test-type: [ 'integration-tests', 'unit-tests', 'gui-test' ]
-        python-version: [ '3.8', '3.11', '3.12' ]
+        python-version: [ '3.12' ]
         os: [ ubuntu-latest ]
     uses: ./.github/workflows/test_ert.yml
     with:
@@ -47,7 +47,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-latest ]
-        python-version: [ '3.8', '3.11', '3.12' ]
+        python-version: [ '3.12' ]
     uses: ./.github/workflows/test_ert_with_slurm.yml
     with:
       os: ${{ matrix.os }}
@@ -81,8 +81,8 @@ jobs:
       fail-fast: false
       matrix:
         test-type: [ 'integration-tests', 'unit-tests', 'gui-test' ]
-        python-version: [ '3.12' ]
-        os: [ 'macos-latest' ]
+        python-version: [ '3.8', '3.11', '3.12' ]
+        os: [ 'macos-14-large' ]
     uses: ./.github/workflows/test_ert.yml
     with:
       os: ${{ matrix.os }}