diff --git a/src/Mod/Sketcher/App/SketchGeometryExtension.cpp b/src/Mod/Sketcher/App/SketchGeometryExtension.cpp
index d1c3867637..af9fa5d3fd 100644
--- a/src/Mod/Sketcher/App/SketchGeometryExtension.cpp
+++ b/src/Mod/Sketcher/App/SketchGeometryExtension.cpp
@@ -31,19 +31,21 @@
 
 using namespace Sketcher;
 
+
 //---------- Geometry Extension
+constexpr std::array<const char *, InternalType::NumInternalGeometryType> SketchGeometryExtension::internaltype2str;
 
 TYPESYSTEM_SOURCE(Sketcher::SketchGeometryExtension,Part::GeometryExtension)
 
 // scoped within the class, multithread ready
 std::atomic<long> SketchGeometryExtension::_GeometryID;
 
-SketchGeometryExtension::SketchGeometryExtension():Id(++SketchGeometryExtension::_GeometryID)
+SketchGeometryExtension::SketchGeometryExtension():Id(++SketchGeometryExtension::_GeometryID),InternalGeometryType(InternalType::None)
 {
 
 }
 
-SketchGeometryExtension::SketchGeometryExtension(long cid):Id(cid)
+SketchGeometryExtension::SketchGeometryExtension(long cid):Id(cid),InternalGeometryType(InternalType::None)
 {
 
 }
@@ -63,7 +65,8 @@ void SketchGeometryExtension::Save(Base::Writer &writer) const
     if(name.size() > 0)
         writer.Stream() << "\" name=\"" << name;
 
-    writer.Stream() << "\" id=\"" << Id << "\"/>" << std::endl;
+    writer.Stream() << "\" id=\"" << Id
+                    << "\" internalGeometryType=\"" << (int) InternalGeometryType << "\"/>" << std::endl;
 }
 
 void SketchGeometryExtension::Restore(Base::XMLReader &reader)
@@ -71,6 +74,7 @@ void SketchGeometryExtension::Restore(Base::XMLReader &reader)
     restoreNameAttribute(reader);
 
     Id = reader.getAttributeAsInteger("id");
+    InternalGeometryType = (InternalType::InternalType) reader.getAttributeAsInteger("internalGeometryType");
 }
 
 std::unique_ptr<Part::GeometryExtension> SketchGeometryExtension::copy(void) const
@@ -78,6 +82,7 @@ std::unique_ptr<Part::GeometryExtension> SketchGeometryExtension::copy(void) con
     auto cpy = std::make_unique<SketchGeometryExtension>();
 
     cpy->Id = this->Id;
+    cpy->InternalGeometryType = this->InternalGeometryType;
 
     cpy->setName(this->getName()); // Base Class
 
diff --git a/src/Mod/Sketcher/App/SketchGeometryExtension.h b/src/Mod/Sketcher/App/SketchGeometryExtension.h
index 1211d97cc2..45c47105ae 100644
--- a/src/Mod/Sketcher/App/SketchGeometryExtension.h
+++ b/src/Mod/Sketcher/App/SketchGeometryExtension.h
@@ -25,10 +25,29 @@
 
 #include <Mod/Part/App/Geometry.h>
 #include <atomic>
+#include <bitset>
+#include <array>
 
 namespace Sketcher
 {
 
+    namespace InternalType {
+        enum InternalType {
+            None                    = 0,
+            EllipseMajorDiameter    = 1,
+            EllipseMinorDiameter    = 2,
+            EllipseFocus1           = 3,
+            EllipseFocus2           = 4,
+            HyperbolaMajor          = 5,
+            HyperbolaMinor          = 6,
+            HyperbolaFocus          = 7,
+            ParabolaFocus           = 8,
+            BSplineControlPoint     = 9,
+            BSplineKnotPoint        = 10,
+            NumInternalGeometryType        // Must be the last
+        };
+    }
+
 class ISketchGeometryExtension
 {
 
@@ -36,12 +55,16 @@ public:
     // Identification information
     virtual long getId() const = 0;
     virtual void setId(long id) = 0;
+
+    virtual InternalType::InternalType getInternalType() const = 0;
+    virtual void setInternalType(InternalType::InternalType type) = 0;
 };
 
 class SketcherExport SketchGeometryExtension : public Part::GeometryExtension, private ISketchGeometryExtension
 {
     TYPESYSTEM_HEADER_WITH_OVERRIDE();
 public:
+
     SketchGeometryExtension();
     SketchGeometryExtension(long cid);
     virtual ~SketchGeometryExtension() override = default;
@@ -58,11 +81,17 @@ public:
     virtual long getId() const override {return Id;}
     virtual void setId(long id) override {Id = id;}
 
+    virtual InternalType::InternalType getInternalType() const override {return InternalGeometryType;}
+    virtual void setInternalType(InternalType::InternalType type) override {InternalGeometryType = type;}
+
+    constexpr static std::array<const char *,InternalType::NumInternalGeometryType> internaltype2str {{ "None", "EllipseMajorDiameter", "EllipseMinorDiameter","EllipseFocus1", "EllipseFocus2", "HyperbolaMajor", "HyperbolaMinor", "HyperbolaFocus", "ParabolaFocus", "BSplineControlPoint", "BSplineKnotPoint" }};
+
 private:
     SketchGeometryExtension(const SketchGeometryExtension&) = default;
 
 private:
-    long Id;
+    long                                Id;
+    InternalType::InternalType    InternalGeometryType;
 
 private:
     static std::atomic<long> _GeometryID;
diff --git a/src/Mod/Sketcher/App/SketchGeometryExtensionPy.xml b/src/Mod/Sketcher/App/SketchGeometryExtensionPy.xml
index 5ace89f320..f3cf557101 100644
--- a/src/Mod/Sketcher/App/SketchGeometryExtensionPy.xml
+++ b/src/Mod/Sketcher/App/SketchGeometryExtensionPy.xml
@@ -23,5 +23,13 @@
         </Documentation>
         <Parameter Name="Id" Type="Long"/>
     </Attribute>
+    <Attribute Name="InternalType" ReadOnly="false">
+        <Documentation>
+            <UserDocu>
+                returns the Id of the SketchGeometryExtension.
+            </UserDocu>
+        </Documentation>
+        <Parameter Name="InternalType" Type="String"/>
+    </Attribute>
   </PythonExport>
 </GenerateModel>
diff --git a/src/Mod/Sketcher/App/SketchGeometryExtensionPyImp.cpp b/src/Mod/Sketcher/App/SketchGeometryExtensionPyImp.cpp
index 8e7bcaa6e8..5d2af73898 100644
--- a/src/Mod/Sketcher/App/SketchGeometryExtensionPyImp.cpp
+++ b/src/Mod/Sketcher/App/SketchGeometryExtensionPyImp.cpp
@@ -89,6 +89,39 @@ void SketchGeometryExtensionPy::setId(Py::Long Id)
     this->getSketchGeometryExtensionPtr()->setId(long(Id));
 }
 
+Py::String SketchGeometryExtensionPy::getInternalType(void) const
+{
+    int internaltypeindex = (int)this->getSketchGeometryExtensionPtr()->getInternalType();
+
+    if(internaltypeindex >= InternalType::NumInternalGeometryType)
+        throw Py::NotImplementedError("String name of enum not implemented");
+
+    std::string typestr = this->getSketchGeometryExtensionPtr()->internaltype2str[internaltypeindex];
+
+     return Py::String(typestr);
+}
+
+void SketchGeometryExtensionPy::setInternalType(Py::String arg)
+{
+    std::string argstr = arg;
+
+    auto pos = std::find_if(this->getSketchGeometryExtensionPtr()->internaltype2str.begin(),
+                                getSketchGeometryExtensionPtr()->internaltype2str.end(),
+                                [argstr](const char * val) {
+                                    return strcmp(val,argstr.c_str())==0;}
+                                );
+
+    if( pos != getSketchGeometryExtensionPtr()->internaltype2str.end()) {
+            int index = std::distance( getSketchGeometryExtensionPtr()->internaltype2str.begin(), pos );
+
+            this->getSketchGeometryExtensionPtr()->setInternalType((InternalType::InternalType)index);
+            return;
+    }
+
+    throw Py::ValueError("Argument is not a valid internal geometry type.");
+}
+
+
 PyObject *SketchGeometryExtensionPy::getCustomAttributes(const char* /*attr*/) const
 {
     return 0;