diff --git a/.github/workflows/macos_python.yml b/.github/workflows/macos_python.yml
index 6134ef4cf2..feb9dcef04 100644
--- a/.github/workflows/macos_python.yml
+++ b/.github/workflows/macos_python.yml
@@ -25,6 +25,9 @@ jobs:
     runs-on: macos-latest
     steps:
     - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.7
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh
@@ -37,6 +40,9 @@ jobs:
     timeout-minutes: 700
     steps:
     - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.7
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh
@@ -48,6 +54,9 @@ jobs:
     runs-on: macos-latest
     steps:
     - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.7
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh
@@ -60,6 +69,9 @@ jobs:
     runs-on: macos-latest
     steps:
     - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.7
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh