diff --git a/src/Gui/PythonWrapper.cpp b/src/Gui/PythonWrapper.cpp
index d11b3c6e22..244cf1c119 100644
--- a/src/Gui/PythonWrapper.cpp
+++ b/src/Gui/PythonWrapper.cpp
@@ -273,7 +273,7 @@ private:
             auto key = wrappers.find(obj);
             if (key != wrappers.end()) {
                 Base::PyGILStateLocker lock;
-                for (auto it : key->second) {
+                for (const auto& it : key->second) {
                     auto value = it.ptr();
                     Shiboken::Object::setValidCpp(reinterpret_cast<SbkObject*>(value), false);
                 }