diff --git a/src/Gui/propertyeditor/PropertyItem.cpp b/src/Gui/propertyeditor/PropertyItem.cpp
index cac1031eaf..3676b2ced7 100644
--- a/src/Gui/propertyeditor/PropertyItem.cpp
+++ b/src/Gui/propertyeditor/PropertyItem.cpp
@@ -206,6 +206,10 @@ void PropertyItem::appendChild(PropertyItem *item)
     childItems.append(item);
 }
 
+/*!
+ * \brief PropertyItem::removeChildren
+ * Deletes the children in the range of [from, to]
+ */
 void PropertyItem::removeChildren(int from, int to)
 {
     int count = to-from+1;
@@ -215,6 +219,17 @@ void PropertyItem::removeChildren(int from, int to)
     }
 }
 
+/*!
+ * \brief PropertyItem::takeChild
+ * Removes the child at index row but doesn't delete it
+ */
+PropertyItem *PropertyItem::takeChild(int row)
+{
+    PropertyItem* child = childItems.takeAt(row);
+    child->setParent(nullptr);
+    return child;
+}
+
 PropertyItem *PropertyItem::child(int row)
 {
     return childItems.value(row);
diff --git a/src/Gui/propertyeditor/PropertyItem.h b/src/Gui/propertyeditor/PropertyItem.h
index 0929cdf735..4ea604c0ea 100644
--- a/src/Gui/propertyeditor/PropertyItem.h
+++ b/src/Gui/propertyeditor/PropertyItem.h
@@ -136,6 +136,7 @@ public:
     PropertyItem *parent() const;
     void appendChild(PropertyItem *child);
     void removeChildren(int from, int to);
+    PropertyItem *takeChild(int);
 
     void setReadOnly(bool);
     bool isReadOnly() const;
diff --git a/src/Gui/propertyeditor/PropertyModel.cpp b/src/Gui/propertyeditor/PropertyModel.cpp
index 597ba8fdea..65b87cdbe9 100644
--- a/src/Gui/propertyeditor/PropertyModel.cpp
+++ b/src/Gui/propertyeditor/PropertyModel.cpp
@@ -208,11 +208,11 @@ QModelIndex PropertyModel::propertyIndexFromPath(const QStringList& path) const
 
 void PropertyModel::buildUp(const PropertyModel::PropertyList& props)
 {
+    beginResetModel();
+
     // fill up the listview with the properties
     rootItem->reset();
 
-    beginResetModel();
-
     // sort the properties into their groups
     std::map<std::string, std::vector<std::vector<App::Property*> > > propGroup;
     PropertyModel::PropertyList::const_iterator jt;
diff --git a/src/Mod/Sketcher/Gui/PropertyConstraintListItem.cpp b/src/Mod/Sketcher/Gui/PropertyConstraintListItem.cpp
index dd3c4ed318..5b1fd069f8 100644
--- a/src/Mod/Sketcher/Gui/PropertyConstraintListItem.cpp
+++ b/src/Mod/Sketcher/Gui/PropertyConstraintListItem.cpp
@@ -124,7 +124,7 @@ void PropertyConstraintListItem::initialize()
     else {
         onlyUnnamed = false;
         if (!unnamed.empty()) {
-            PropertyConstraintListItem* item = static_cast<PropertyConstraintListItem*>(PropertyConstraintListItem::create()); 
+            PropertyConstraintListItem* item = static_cast<PropertyConstraintListItem*>(PropertyConstraintListItem::create());
             item->setParent(this);
             item->setPropertyName(tr("Unnamed"));
             this->appendChild(item);
@@ -137,6 +137,98 @@ void PropertyConstraintListItem::initialize()
     }
 }
 
+void PropertyConstraintListItem::assignProperty(const App::Property* prop)
+{
+    // Hint: When renaming a constraint that was unnamed before then it can happen that
+    // a constraint appears twice in the property editor, one time in this group and a
+    // second time inside the Unnamed group
+    if (!prop->getTypeId().isDerivedFrom(Sketcher::PropertyConstraintList::getClassTypeId()))
+        return;
+
+    const Sketcher::PropertyConstraintList* list = static_cast<const Sketcher::PropertyConstraintList*>(prop);
+    const std::vector< Sketcher::Constraint * > &vals = list->getValues();
+
+    // search for the group of unnamed items if available and take it out
+    int numUnnamed = 0;
+    PropertyConstraintListItem* unnamed = nullptr;
+    for (int i = this->childCount() - 1; i >= 0; i--) {
+        unnamed = qobject_cast<PropertyConstraintListItem*>(this->child(i));
+        if (unnamed) {
+            numUnnamed = unnamed->childCount();
+            this->takeChild(i);
+            break;
+        }
+    }
+
+    int id = 1;
+    int namedIndex = 0;
+    int unnamedIndex = 0;
+    int numNamed = this->childCount();
+    this->onlyUnnamed = true;
+
+    for (std::vector< Sketcher::Constraint* >::const_iterator it = vals.begin();it != vals.end(); ++it, ++id) {
+        if ((*it)->Type == Sketcher::Distance || // Datum constraint
+            (*it)->Type == Sketcher::DistanceX ||
+            (*it)->Type == Sketcher::DistanceY ||
+            (*it)->Type == Sketcher::Radius ||
+            (*it)->Type == Sketcher::Angle ) {
+
+            PropertyUnitItem* child = nullptr;
+            if ((*it)->Name.empty()) {
+                // search inside the group item for unnamed constraints
+                if (!unnamed) {
+                    unnamed = static_cast<PropertyConstraintListItem*>(PropertyConstraintListItem::create());
+                    unnamed->setPropertyName(tr("Unnamed"));
+                }
+
+                if (unnamedIndex < numUnnamed) {
+                    child = static_cast<PropertyUnitItem*>(unnamed->child(unnamedIndex));
+                }
+                else {
+                    child = static_cast<PropertyUnitItem*>(PropertyUnitItem::create());
+                    unnamed->appendChild(child);
+                    child->setParent(unnamed);
+                }
+                unnamedIndex++;
+            }
+            else {
+                // search inside this item
+                if (namedIndex < numNamed)
+                    child = dynamic_cast<PropertyUnitItem*>(this->child(namedIndex));
+
+                if (!child) {
+                    child = static_cast<PropertyUnitItem*>(PropertyUnitItem::create());
+                    this->appendChild(child);
+                    child->setParent(this);
+                }
+                namedIndex++;
+                this->onlyUnnamed = false;
+            }
+
+            // Get the name
+            QString internalName = QString::fromLatin1("Constraint%1").arg(id);
+            QString name = QString::fromUtf8((*it)->Name.c_str());
+            if (name.isEmpty()) {
+                name = internalName;
+            }
+
+            if (child->objectName() != internalName) {
+                child->setPropertyName(name);
+                child->setObjectName(internalName);
+
+                child->bind(list->createPath(id-1));
+                child->setAutoApply(false);
+            }
+        }
+    }
+
+    // at the Unnamed group at very the end
+    if (unnamed) {
+        this->appendChild(unnamed);
+        unnamed->setParent(this);
+    }
+}
+
 QVariant PropertyConstraintListItem::value(const App::Property* prop) const
 {
     assert(prop && prop->getTypeId().isDerivedFrom(Sketcher::PropertyConstraintList::getClassTypeId()));
@@ -173,9 +265,6 @@ QVariant PropertyConstraintListItem::value(const App::Property* prop) const
             // Use a 7-bit ASCII string for the internal name.
             // See also comment in PropertyConstraintListItem::initialize()
             QString internalName = QString::fromLatin1("Constraint%1").arg(id);
-            PropertyConstraintListItem* self = const_cast<PropertyConstraintListItem*>(this);
-
-            self->blockEvent = true;
 
             if ((*it)->Name.empty() && !onlyUnnamed) {
                 onlyNamed = false;
@@ -193,10 +282,10 @@ QVariant PropertyConstraintListItem::value(const App::Property* prop) const
                 }
             }
             else {
+                self->blockEvent = true;
                 self->setProperty(internalName.toLatin1(), QVariant::fromValue<Base::Quantity>(quant));
+                self->blockEvent = false;
             }
-
-            self->blockEvent = false;
         }
     }
 
diff --git a/src/Mod/Sketcher/Gui/PropertyConstraintListItem.h b/src/Mod/Sketcher/Gui/PropertyConstraintListItem.h
index e3ae30d4fd..8afe43ba44 100644
--- a/src/Mod/Sketcher/Gui/PropertyConstraintListItem.h
+++ b/src/Mod/Sketcher/Gui/PropertyConstraintListItem.h
@@ -46,6 +46,7 @@ class PropertyConstraintListItem: public Gui::PropertyEditor::PropertyItem
     PROPERTYITEM_HEADER
 
     virtual ~PropertyConstraintListItem();
+    virtual void assignProperty(const App::Property* prop);
     virtual QWidget* createEditor(QWidget* parent, const QObject* receiver, const char* method) const;
     virtual void setEditorData(QWidget *editor, const QVariant& data) const;
     virtual QVariant editorData(QWidget *editor) const;