diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index d7121002d..cd2374086 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -43,11 +43,10 @@ jobs:
     - name: Install python packages
       shell: bash -el {0}
       run: |
+        python -m pip install --upgrade pip
+        python -m pip install pyqt${{ matrix.pyqt-version }} -r requirements.txt -r dev-requirements.txt
         if [ "$RUNNER_OS" == "Windows" ]; then
-          mamba install pyqt=${{ matrix.pyqt-version }}
-          mamba install --file requirements.txt --file windows-dev-requirements.txt
-        else
-          mamba install pyqt=${{ matrix.pyqt-version }} $(cat requirements.txt dev-requirements.txt)
+          python -m pip install -r windows-dev-requirements.txt
         fi
     - name: Install packages for testing a pyqt app on linux
       shell: bash -el {0}