diff --git a/.github/workflows/_WindowsInstaller.yml b/.github/workflows/_WindowsInstaller.yml
index f2def8b74..b070adbf8 100644
--- a/.github/workflows/_WindowsInstaller.yml
+++ b/.github/workflows/_WindowsInstaller.yml
@@ -37,7 +37,7 @@ jobs:
           pip install $(python -c "import glob; print(' '.join(glob.glob('wheels/*cp313*.whl')))") 
           pip install Cython
           pip install numpy==2.2.6 
-          pip install Pyside6==6.9.1
+          pip install Pyside6==6.8.3
           pip install h5py
           pip install fisx
           pip install hdf5plugin
diff --git a/src/PyMca5/PyMcaGui/pymca/PyMcaMain.py b/src/PyMca5/PyMcaGui/pymca/PyMcaMain.py
index 2e2e68a42..d3c22cf54 100644
--- a/src/PyMca5/PyMcaGui/pymca/PyMcaMain.py
+++ b/src/PyMca5/PyMcaGui/pymca/PyMcaMain.py
@@ -187,10 +187,12 @@
 if __name__ == "__main__":
     sys.excepthook = qt.exceptionHandler
 
-    # To avoid "Dark mode"; this force main windows to be light (but not all submenus)
     if sys.platform == 'win32':
+        # To avoid "Dark mode"; this force main windows to be light (but not all submenus)
         _ = os.environ.setdefault("QT_QPA_PLATFORM", "windows:darkmode=0")
-    
+        # minimal fix for matplotlib fonts when Windows scale (DPI) is not 100%
+        _ = os.environ["QT_ENABLE_HIGHDPI_SCALING"] = "0"
+
     app = qt.QApplication(sys.argv)
     
     # To avoid "Dark mode"; without this part some menus will be still dark