diff --git a/.github/workflows/osgeo4w.yml b/.github/workflows/osgeo4w.yml
index 96b5a6bb9aa..44fcd4f5803 100644
--- a/.github/workflows/osgeo4w.yml
+++ b/.github/workflows/osgeo4w.yml
@@ -129,6 +129,7 @@ jobs:
           python -m pip install ^
             pytest ^
             pytest-timeout ^
+            pytest-cov ^
             pytest-xdist ^
             pytest-randomly
         # Obfuscated usage of GitHub Actions features, Windows CMD shell limits analysis
@@ -138,8 +139,11 @@ jobs:
           call %OSGEO4W_ROOT%\opt\grass\etc\env.bat
           set PYTHONPATH=%GISBASE%\etc\python;%PYTHONPATH%
           path %GISBASE%\lib;%GISBASE%\bin;%PATH%
+          set INITIAL_GISBASE=%GISBASE%
+          set INITIAL_PWD=%CD%
           pytest ^
             @.github/workflows/pytest_args_ci.txt ^
+            @.github/workflows/pytest_args_cov.txt ^
             @.github/workflows/pytest_args_parallel.txt ^
             --junitxml=pytest.xdist.junit.xml ^
             -k "not testsuite"
@@ -152,8 +156,11 @@ jobs:
           call %OSGEO4W_ROOT%\opt\grass\etc\env.bat
           set PYTHONPATH=%GISBASE%\etc\python;%PYTHONPATH%
           path %GISBASE%\lib;%GISBASE%\bin;%PATH%
+          set INITIAL_GISBASE=%GISBASE%
+          set INITIAL_PWD=%CD%
           pytest ^
             @.github/workflows/pytest_args_ci.txt ^
+            @.github/workflows/pytest_args_cov.txt ^
             @.github/workflows/pytest_args_not_parallel.txt ^
             --junitxml=pytest.needs_solo_run.junit.xml ^
             -k "not testsuite"
@@ -164,13 +171,30 @@ jobs:
           call %OSGEO4W_ROOT%\opt\grass\etc\env.bat
           set PYTHONPATH=%GISBASE%\etc\python;%PYTHONPATH%
           path %GISBASE%\lib;%GISBASE%\bin;%PATH%;%OSGEO4W_ROOT%\opt\grass
+          set INITIAL_GISBASE=%GISBASE%
+          set INITIAL_PWD=%CD%
           pytest ^
             @.github/workflows/pytest_args_ci.txt ^
+            @.github/workflows/pytest_args_cov.txt ^
             @.github/workflows/pytest_args_deselect.txt ^
             @.github/workflows/pytest_args_gunittest.txt ^
             --junitxml=pytest.gunittest.junit.xml
         # Obfuscated usage of GitHub Actions features, Windows CMD shell limits analysis
         shell: cmd /D /E:ON /V:OFF /S /C "CALL C:/OSGeo4W/OSGeo4W.bat "{0}"" # zizmor: ignore[misfeature]
+      - name: Fix non-standard installed script paths in coverage data
+        run: |
+          call %OSGEO4W_ROOT%\opt\grass\etc\env.bat
+          set PYTHONPATH=%GISBASE%\etc\python;%PYTHONPATH%
+          path %GISBASE%\lib;%GISBASE%\bin;%PATH%
+          set INITIAL_GISBASE=%GISBASE%
+          set INITIAL_PWD=%CD%
+          python utils/coverage_mapper.py
+          coverage combine
+          coverage html
+          coverage report
+          coverage json
+        # Obfuscated usage of GitHub Actions features, Windows CMD shell limits analysis
+        shell: cmd /D /E:ON /V:OFF /S /C "CALL C:/OSGeo4W/OSGeo4W.bat "{0}"" # zizmor: ignore[misfeature]
 
       - name: Upload test results to Codecov
         if: ${{ !cancelled() }}
@@ -180,6 +204,20 @@ jobs:
           flags: ${{ matrix.os }}-pytest-python
           token: ${{ secrets.CODECOV_TOKEN }}
           report_type: test_results
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f # v7.0.0
+        with:
+          verbose: true
+          flags: pytest-osgeo4w
+          name: pytest-osgeo4w
+          token: ${{ secrets.CODECOV_TOKEN }}
+      - name: Make python-only code coverage test report available
+        if: ${{ !cancelled() }}
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: python-codecoverage-report-${{ matrix.os }}
+          path: coverage_html_report
+          retention-days: 1
 
       - name: Run tests
         run: .github/workflows/test_thorough.bat '%O4WROOT%\opt\grass\grass86.bat' '%O4WROOT%\bin\python3'
diff --git a/general/g.version/tests/conftest.py b/general/g.version/tests/conftest.py
index e4357b2f672..9ed72d55038 100644
--- a/general/g.version/tests/conftest.py
+++ b/general/g.version/tests/conftest.py
@@ -3,11 +3,12 @@
 import grass.script as gs
 
 
-@pytest.fixture(scope="module")
-def session(tmp_path_factory):
+@pytest.fixture
+def session(tmp_path_factory, monkeypatch):
     """Set up a GRASS session for the tests."""
     tmp_path = tmp_path_factory.mktemp("grass_session")
     project = "test_project"
+    monkeypatch.delenv("GISBASE", raising=False)
 
     # Create a test location
     gs.create_project(tmp_path, project)