diff --git a/src/Gui/Workbench.cpp b/src/Gui/Workbench.cpp
index 532b20d7c7..f44bf2ea0e 100644
--- a/src/Gui/Workbench.cpp
+++ b/src/Gui/Workbench.cpp
@@ -1057,6 +1057,7 @@ PythonBaseWorkbench::~PythonBaseWorkbench()
     delete _toolBar;
     delete _commandBar;
     if (_workbenchPy) {
+        Base::PyGILStateLocker lock;
         _workbenchPy->setInvalid();
         _workbenchPy->DecRef();
     }