diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 0e03be953c..11252d81e4 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1555,6 +1555,7 @@ def ensure_app(headless=True):
                     os.environ['QT_MAC_DISABLE_FOREGROUND_APPLICATION_TRANSFORM'] = '1'
             if headless and iswindows:
                 QApplication.setAttribute(Qt.ApplicationAttribute.AA_UseSoftwareOpenGL, True)
+            QApplication.setAttribute(Qt.ApplicationAttribute.AA_ShareOpenGLContexts)
             _store_app = QApplication(args)
             if headless and has_headless:
                 _store_app.headless = True