diff --git a/.github/workflows/test_linux.yml b/.github/workflows/test_linux.yml
index b03be47..c0a3469 100644
--- a/.github/workflows/test_linux.yml
+++ b/.github/workflows/test_linux.yml
@@ -18,7 +18,7 @@ jobs:
     - uses: actions/setup-python@v5
       name: Install Python
       with:
-        python-version: '3.9'
+        python-version: '3.7'
 
     - name: install python packages
       run: python3 -m pip install numpy scipy
diff --git a/.github/workflows/test_macos.yml b/.github/workflows/test_macos.yml
index 383c39f..99a1fec 100644
--- a/.github/workflows/test_macos.yml
+++ b/.github/workflows/test_macos.yml
@@ -18,7 +18,7 @@ jobs:
     - uses: actions/setup-python@v5
       name: Install Python
       with:
-        python-version: '3.9'
+        python-version: '3.7'
 
     - name: install python packages
       run: python3 -m pip install numpy scipy
diff --git a/.github/workflows/test_windows.yml b/.github/workflows/test_windows.yml
index 4a7fc2c..3d7e8d5 100644
--- a/.github/workflows/test_windows.yml
+++ b/.github/workflows/test_windows.yml
@@ -18,7 +18,7 @@ jobs:
     - uses: actions/setup-python@v5
       name: Install Python
       with:
-        python-version: '3.9'
+        python-version: '3.7'
     
     - name: install python packages
       run: python -m pip install numpy scipy