diff --git a/src/Mod/PartDesign/App/DatumLine.cpp b/src/Mod/PartDesign/App/DatumLine.cpp
index 3682265798..1134344fe4 100644
--- a/src/Mod/PartDesign/App/DatumLine.cpp
+++ b/src/Mod/PartDesign/App/DatumLine.cpp
@@ -362,12 +362,13 @@ void Line::onChanged(const App::Property *prop)
         if (p1 != NULL) delete p1;
         if (p2 != NULL) delete p2;
         if (line != NULL) delete line;
+        if (circle != NULL) delete circle;
     }
 
     Part::Datum::onChanged(prop);
 }
 
-const std::set<QString> Line::getHint()
+const std::set<QString> Line::getHint() const
 {
     if (hints.find(refTypes) != hints.end())
         return hints[refTypes];
diff --git a/src/Mod/PartDesign/App/DatumLine.h b/src/Mod/PartDesign/App/DatumLine.h
index 14eaf3ef15..b678536492 100644
--- a/src/Mod/PartDesign/App/DatumLine.h
+++ b/src/Mod/PartDesign/App/DatumLine.h
@@ -45,7 +45,8 @@ public:
     }
 
     static void initHints();
-    const std::set<QString> getHint();
+    const std::set<QString> getHint() const;
+    const int offsetsAllowed() const;
 
     Base::Vector3d getBasePoint() const;
     Base::Vector3d getDirection() const;
diff --git a/src/Mod/PartDesign/App/DatumPlane.cpp b/src/Mod/PartDesign/App/DatumPlane.cpp
index 6415b5e1f1..0ab7582b0d 100644
--- a/src/Mod/PartDesign/App/DatumPlane.cpp
+++ b/src/Mod/PartDesign/App/DatumPlane.cpp
@@ -358,7 +358,7 @@ void Plane::onChanged(const App::Property *prop)
 }
 
 
-const std::set<QString> Plane::getHint()
+const std::set<QString> Plane::getHint() const
 {
     if (hints.find(refTypes) != hints.end())
         return hints[refTypes];
diff --git a/src/Mod/PartDesign/App/DatumPlane.h b/src/Mod/PartDesign/App/DatumPlane.h
index d64ed69004..3d78165b64 100644
--- a/src/Mod/PartDesign/App/DatumPlane.h
+++ b/src/Mod/PartDesign/App/DatumPlane.h
@@ -44,7 +44,8 @@ public:
     }
 
     static void initHints();
-    const std::set<QString> getHint();
+    const std::set<QString> getHint() const;
+    const int offsetsAllowed() const;
 
     Base::Vector3d getBasePoint();
     Base::Vector3d getNormal();
diff --git a/src/Mod/PartDesign/App/DatumPoint.cpp b/src/Mod/PartDesign/App/DatumPoint.cpp
index b60412fe7f..1a3d9b667c 100644
--- a/src/Mod/PartDesign/App/DatumPoint.cpp
+++ b/src/Mod/PartDesign/App/DatumPoint.cpp
@@ -362,7 +362,7 @@ Base::Vector3d Point::getPoint()
 }
 
 
-const std::set<QString> Point::getHint()
+const std::set<QString> Point::getHint() const
 {
     if (hints.find(refTypes) != hints.end())
         return hints[refTypes];
diff --git a/src/Mod/PartDesign/App/DatumPoint.h b/src/Mod/PartDesign/App/DatumPoint.h
index 8f9be2b2da..0a23e064d2 100644
--- a/src/Mod/PartDesign/App/DatumPoint.h
+++ b/src/Mod/PartDesign/App/DatumPoint.h
@@ -45,7 +45,8 @@ public:
     }
 
     static void initHints();
-    const std::set<QString> getHint();
+    const std::set<QString> getHint() const;
+    const int offsetsAllowed() const;
 
     Base::Vector3d getPoint();