diff --git a/src/Gui/Application.cpp b/src/Gui/Application.cpp
index 02da32008c..ad14a9ce9c 100644
--- a/src/Gui/Application.cpp
+++ b/src/Gui/Application.cpp
@@ -606,12 +606,13 @@ void Application::exportTo(const char* FileName, const char* DocName, const char
             }
 
             std::stringstream str;
-			std::set<App::DocumentObject*> unique_objs;
+            std::set<App::DocumentObject*> unique_objs;
             str << "__objs__=[]" << std::endl;
             for (std::vector<App::DocumentObject*>::iterator it = sel.begin(); it != sel.end(); ++it) {
-				if (unique_objs.insert(*it).second)
-					str << "__objs__.append(FreeCAD.getDocument(\"" << DocName << "\").getObject(\""
-						<< (*it)->getNameInDocument() << "\"))" << std::endl;
+                if (unique_objs.insert(*it).second) {
+                    str << "__objs__.append(FreeCAD.getDocument(\"" << DocName << "\").getObject(\""
+                        << (*it)->getNameInDocument() << "\"))" << std::endl;
+                }
             }
 
             str << "import " << Module << std::endl;
diff --git a/src/Gui/CommandDoc.cpp b/src/Gui/CommandDoc.cpp
index abe4073bd0..8f2b245bf9 100644
--- a/src/Gui/CommandDoc.cpp
+++ b/src/Gui/CommandDoc.cpp
@@ -928,10 +928,12 @@ StdCmdDuplicateSelection::StdCmdDuplicateSelection()
 void StdCmdDuplicateSelection::activated(int iMsg)
 {
     std::vector<SelectionSingleton::SelObj> sel = Selection().getCompleteSelection();
+    std::set<App::DocumentObject*> unique_objs;
     std::map< App::Document*, std::vector<App::DocumentObject*> > objs;
     for (std::vector<SelectionSingleton::SelObj>::iterator it = sel.begin(); it != sel.end(); ++it) {
         if (it->pObject && it->pObject->getDocument()) {
-            objs[it->pObject->getDocument()].push_back(it->pObject);
+            if (unique_objs.insert(it->pObject).second)
+                objs[it->pObject->getDocument()].push_back(it->pObject);
         }
     }
 
diff --git a/src/Gui/MainWindow.cpp b/src/Gui/MainWindow.cpp
index 33d651e118..f73a88444e 100644
--- a/src/Gui/MainWindow.cpp
+++ b/src/Gui/MainWindow.cpp
@@ -1318,12 +1318,12 @@ void MainWindow::dragEnterEvent (QDragEnterEvent * e)
 QMimeData * MainWindow::createMimeDataFromSelection () const
 {
     std::vector<SelectionSingleton::SelObj> selobj = Selection().getCompleteSelection();
-	std::set<App::DocumentObject*> unique_objs;
+    std::set<App::DocumentObject*> unique_objs;
     std::map< App::Document*, std::vector<App::DocumentObject*> > objs;
     for (std::vector<SelectionSingleton::SelObj>::iterator it = selobj.begin(); it != selobj.end(); ++it) {
         if (it->pObject && it->pObject->getDocument()) {
-			if (unique_objs.insert(it->pObject).second)
-	            objs[it->pObject->getDocument()].push_back(it->pObject);
+            if (unique_objs.insert(it->pObject).second)
+                objs[it->pObject->getDocument()].push_back(it->pObject);
         }
     }