diff --git a/src/Mod/Assembly/Gui/ViewProviderConstraint.cpp b/src/Mod/Assembly/Gui/ViewProviderConstraint.cpp
index bc00eb8aa..19445eba2 100644
--- a/src/Mod/Assembly/Gui/ViewProviderConstraint.cpp
+++ b/src/Mod/Assembly/Gui/ViewProviderConstraint.cpp
@@ -103,6 +103,21 @@ void ViewProviderConstraintInternal::switch_node(bool onoff)
         pcModeSwitch->whichChild = -1;
 }
 
+void ViewProviderConstraint::setDisplayMode(const char* ModeName) 
+{
+         setDisplayMaskMode("Flat Lines");
+  
+}
+
+std::vector<std::string> ViewProviderConstraint::getDisplayModes(void) const
+{
+    std::vector<std::string> StrList;
+
+    // add your own mode
+    StrList.push_back("Flat Lines");
+    return StrList;
+}
+
 
 PROPERTY_SOURCE(AssemblyGui::ViewProviderConstraint, PartGui::ViewProviderPart)
 
diff --git a/src/Mod/Assembly/Gui/ViewProviderConstraint.h b/src/Mod/Assembly/Gui/ViewProviderConstraint.h
index 2e963bd65..f343b7cc2 100644
--- a/src/Mod/Assembly/Gui/ViewProviderConstraint.h
+++ b/src/Mod/Assembly/Gui/ViewProviderConstraint.h
@@ -87,6 +87,10 @@ public:
     //avoid unneeded context menu entrys
     virtual void setupContextMenu(QMenu* menu, QObject* receiver, const char* member);
 
+    //only flat lines supported
+    virtual void setDisplayMode(const char* ModeName);
+    virtual std::vector<std::string> getDisplayModes(void) const;
+    
 private:
     //we need two seperate visual representations, as both constraint parts have different
     //placements.