diff --git a/.github/workflows/condaWF.yml b/.github/workflows/condaWF.yml
index 8ba082fc1e..a83516fc7e 100644
--- a/.github/workflows/condaWF.yml
+++ b/.github/workflows/condaWF.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04 , macos-12 , macos-14 ]
+        os: [ubuntu-20.04 , macos-13 , macos-14 ]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
diff --git a/.github/workflows/macWF.yml b/.github/workflows/macWF.yml
index e927188b29..8a006975a4 100644
--- a/.github/workflows/macWF.yml
+++ b/.github/workflows/macWF.yml
@@ -21,7 +21,7 @@ jobs:
       matrix:
         variant: [ "" , "+allmodules" ]
         # this is to test both intel and arm64 macs
-        os: [ macos-12 , macos-14 ]
+        os: [ macos-13 , macos-14 ]
         exclude:
         # many tests on contributed modules are still failing for numerical reasons on arm64, see https://github.com/plumed/plumed2/pull/950
         # once fixed we could introduce this back:
@@ -68,7 +68,7 @@ jobs:
       fail-fast: false
       matrix:
         # this is to test both intel and arm64 macs
-        os: [ macos-12 , macos-14 ]
+        os: [ macos-13 , macos-14 ]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index f52cccebb0..2bb42a34e8 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest , macos-12 , macos-14]
+        os: [ubuntu-latest , macos-13 , macos-14]
         branch: [v2.8, v2.9, master]
     runs-on: ${{ matrix.os }}
     steps: