diff --git a/src/Mod/Sketcher/App/PropertyConstraintList.cpp b/src/Mod/Sketcher/App/PropertyConstraintList.cpp
index ae98ce409..6e9bb35c2 100644
--- a/src/Mod/Sketcher/App/PropertyConstraintList.cpp
+++ b/src/Mod/Sketcher/App/PropertyConstraintList.cpp
@@ -232,24 +232,41 @@ void PropertyConstraintList::applyValidGeometryKeys(const std::vector<unsigned i
 
 void PropertyConstraintList::checkGeometry(const std::vector<Part::Geometry *> &GeoList)
 {
-    if (validGeometryKeys.size() != GeoList.size()) {
+    if (!scanGeometry(GeoList)) {
         invalidGeometry = true;
         return;
     }
 
+    //if we made it here, geometry is OK
+    if (invalidGeometry) {
+        //geometry was bad, but now it became OK.
+        invalidGeometry = false;
+        touch();
+    }
+}
+
+/*!
+ * \brief PropertyConstraintList::scanGeometry tests if the supplied geometry
+ *  is the same (all elements are of the same type as they used to be).
+ * \param GeoList - new geometry list to be checked
+ * \return false, if the types have changed.
+ */
+bool PropertyConstraintList::scanGeometry(const std::vector<Part::Geometry *> &GeoList) const
+{
+    if (validGeometryKeys.size() != GeoList.size()) {
+        return false;
+    }
+
     unsigned int i=0;
     for (std::vector< Part::Geometry * >::const_iterator it=GeoList.begin();
          it != GeoList.end(); ++it, i++) {
         if (validGeometryKeys[i] != (*it)->getTypeId().getKey()) {
-            invalidGeometry = true;
-            return;
+            return false;
         }
     }
 
-    if (invalidGeometry) {
-        invalidGeometry = false;
-        touch();
-    }
+    return true;
 }
 
+
 std::vector<Constraint *> PropertyConstraintList::_emptyValueList(0);
diff --git a/src/Mod/Sketcher/App/PropertyConstraintList.h b/src/Mod/Sketcher/App/PropertyConstraintList.h
index df99b4b3f..1726d7500 100644
--- a/src/Mod/Sketcher/App/PropertyConstraintList.h
+++ b/src/Mod/Sketcher/App/PropertyConstraintList.h
@@ -79,6 +79,9 @@ public:
     const std::vector<Constraint*> &getValues(void) const {
         return invalidGeometry ? _emptyValueList : _lValueList;
     }
+    const std::vector<Constraint*> &getValuesForce(void) const {//to suppress check for invalid geometry, to be used for sketch repairing.
+        return  _lValueList;
+    }
 
     virtual PyObject *getPyObject(void);
     virtual void setPyObject(PyObject *);
@@ -93,6 +96,8 @@ public:
 
     void acceptGeometry(const std::vector<Part::Geometry *> &GeoList);
     void checkGeometry(const std::vector<Part::Geometry *> &GeoList);
+    bool scanGeometry(const std::vector<Part::Geometry *> &GeoList) const;
+    bool isGeometryInvalid(){return invalidGeometry;}
 
 private:
     std::vector<Constraint *> _lValueList;
diff --git a/src/Mod/Sketcher/App/SketchObject.cpp b/src/Mod/Sketcher/App/SketchObject.cpp
index c7a938aa8..35f6fa0bc 100644
--- a/src/Mod/Sketcher/App/SketchObject.cpp
+++ b/src/Mod/Sketcher/App/SketchObject.cpp
@@ -1756,7 +1756,7 @@ int SketchObject::delExternal(int ExtGeoId)
 
 int SketchObject::delConstraintsToExternal()
 {
-    const std::vector< Constraint * > &constraints = Constraints.getValues();
+    const std::vector< Constraint * > &constraints = Constraints.getValuesForce();
     std::vector< Constraint * > newConstraints(0);
     int GeoId = -3, NullId = -2000;
     for (std::vector<Constraint *>::const_iterator it = constraints.begin();
@@ -2270,7 +2270,7 @@ bool SketchObject::evaluateConstraints() const
     int extGeoCount = getExternalGeometryCount();
 
     std::vector<Part::Geometry *> geometry = getCompleteGeometry();
-    const std::vector<Sketcher::Constraint *>& constraints = Constraints.getValues();
+    const std::vector<Sketcher::Constraint *>& constraints = Constraints.getValuesForce();
     if (static_cast<int>(geometry.size()) != extGeoCount + intGeoCount)
         return false;
     if (geometry.size() < 2)
@@ -2282,6 +2282,10 @@ bool SketchObject::evaluateConstraints() const
             return false;
     }
 
+    if(constraints.size()>0){
+        if (!Constraints.scanGeometry(geometry)) return false;
+    }
+
     return true;
 }