diff --git a/python/core/geometry/qgsabstractgeometryv2.sip b/python/core/geometry/qgsabstractgeometryv2.sip
index 3cd3ab502c1..aa66e56d2f1 100644
--- a/python/core/geometry/qgsabstractgeometryv2.sip
+++ b/python/core/geometry/qgsabstractgeometryv2.sip
@@ -306,6 +306,12 @@ class QgsAbstractGeometryV2
      */
     virtual QgsAbstractGeometryV2* segmentize() const /Factory/;
 
+    /** Returns the geometry converted to the more generic curve type.
+        E.g. QgsLineStringV2 -> QgsCompoundCurveV2, QgsPolygonV2 -> QgsCurvePolygonV2,
+        QgsMultiLineStringV2 -> QgsMultiCurveV2, QgsMultiPolygonV2 -> QgsMultiSurfaceV2
+        @return the converted geometry. Caller takes ownership*/
+    virtual QgsAbstractGeometryV2* toCurveType() const /Factory/;
+
     /** Returns approximate angle at a vertex. This is usually the average angle between adjacent
      * segments, and can be pictured as the orientation of a line following the curvature of the
      * geometry at the specified vertex.
diff --git a/python/core/geometry/qgslinestringv2.sip b/python/core/geometry/qgslinestringv2.sip
index fad5fca934c..dc5ead486bb 100644
--- a/python/core/geometry/qgslinestringv2.sip
+++ b/python/core/geometry/qgslinestringv2.sip
@@ -106,6 +106,10 @@ class QgsLineStringV2: public QgsCurveV2
      */
     QPolygonF asQPolygonF() const;
 
+    /** Returns the geometry converted to the more generic curve type QgsCompoundCurveV2
+        @return the converted geometry. Caller takes ownership*/
+    QgsAbstractGeometryV2* toCurveType() const /Factory/;
+
     //reimplemented methods
 
     virtual QString geometryType() const;
diff --git a/python/core/geometry/qgsmultilinestringv2.sip b/python/core/geometry/qgsmultilinestringv2.sip
index c1833e74975..f42c39ec53c 100644
--- a/python/core/geometry/qgsmultilinestringv2.sip
+++ b/python/core/geometry/qgsmultilinestringv2.sip
@@ -20,6 +20,10 @@ class QgsMultiLineStringV2: public QgsMultiCurveV2
     /** Adds a geometry and takes ownership. Returns true in case of success*/
     virtual bool addGeometry( QgsAbstractGeometryV2* g );
 
+    /** Returns the geometry converted to the more generic curve type QgsMultiCurveV2
+    @return the converted geometry. Caller takes ownership*/
+    QgsAbstractGeometryV2* toCurveType() const /Factory/;
+
   protected:
 
     virtual bool wktOmitChildType() const;
diff --git a/python/core/geometry/qgsmultipolygonv2.sip b/python/core/geometry/qgsmultipolygonv2.sip
index 26392e2e1e7..f5d5ebd4e31 100644
--- a/python/core/geometry/qgsmultipolygonv2.sip
+++ b/python/core/geometry/qgsmultipolygonv2.sip
@@ -20,6 +20,10 @@ class QgsMultiPolygonV2: public QgsMultiSurfaceV2
     /** Adds a geometry and takes ownership. Returns true in case of success*/
     virtual bool addGeometry( QgsAbstractGeometryV2* g );
 
+    /** Returns the geometry converted to the more generic curve type QgsMultiSurfaceV2
+    @return the converted geometry. Caller takes ownership*/
+    QgsAbstractGeometryV2* toCurveType() const /Factory/;
+
   protected:
 
     virtual bool wktOmitChildType() const;
diff --git a/python/core/geometry/qgspolygonv2.sip b/python/core/geometry/qgspolygonv2.sip
index f52273e6589..fb38cd87372 100644
--- a/python/core/geometry/qgspolygonv2.sip
+++ b/python/core/geometry/qgspolygonv2.sip
@@ -26,6 +26,10 @@ class QgsPolygonV2: public QgsCurvePolygonV2
 
     QgsPolygonV2* surfaceToPolygon() const;
 
+    /** Returns the geometry converted to the more generic curve type QgsCurvePolygonV2
+     @return the converted geometry. Caller takes ownership*/
+    QgsAbstractGeometryV2* toCurveType() const /Factory/;
+
     void addInteriorRing( QgsCurveV2* ring /Transfer/ );
     //overridden to handle LineString25D rings
     virtual void setExteriorRing( QgsCurveV2* ring /Transfer/ );
diff --git a/src/core/geometry/qgsabstractgeometryv2.h b/src/core/geometry/qgsabstractgeometryv2.h
index 9057cebadd1..5863a97cc8e 100644
--- a/src/core/geometry/qgsabstractgeometryv2.h
+++ b/src/core/geometry/qgsabstractgeometryv2.h
@@ -294,7 +294,8 @@ class CORE_EXPORT QgsAbstractGeometryV2
 
     /** Returns the geometry converted to the more generic curve type.
         E.g. QgsLineStringV2 -> QgsCompoundCurveV2, QgsPolygonV2 -> QgsCurvePolygonV2,
-        QgsMultiLineStringV2 -> QgsMultiCurveV2, QgsMultiPolygonV2 -> QgsMultiSurfaceV2*/
+        QgsMultiLineStringV2 -> QgsMultiCurveV2, QgsMultiPolygonV2 -> QgsMultiSurfaceV2
+        @return the converted geometry. Caller takes ownership*/
     virtual QgsAbstractGeometryV2* toCurveType() const { return 0; }
 
     /** Returns approximate angle at a vertex. This is usually the average angle between adjacent
diff --git a/src/core/geometry/qgslinestringv2.h b/src/core/geometry/qgslinestringv2.h
index 16677d56287..76e250d3b45 100644
--- a/src/core/geometry/qgslinestringv2.h
+++ b/src/core/geometry/qgslinestringv2.h
@@ -132,7 +132,8 @@ class CORE_EXPORT QgsLineStringV2: public QgsCurveV2
      */
     QPolygonF asQPolygonF() const;
 
-    /** Returns the geometry converted to QgsCompoundCurveV2*/
+    /** Returns the geometry converted to the more generic curve type QgsCompoundCurveV2
+        @return the converted geometry. Caller takes ownership*/
     QgsAbstractGeometryV2* toCurveType() const override;
 
     //reimplemented methods
diff --git a/src/core/geometry/qgsmultilinestringv2.h b/src/core/geometry/qgsmultilinestringv2.h
index 6e28ad4728d..1516893d34a 100644
--- a/src/core/geometry/qgsmultilinestringv2.h
+++ b/src/core/geometry/qgsmultilinestringv2.h
@@ -42,7 +42,8 @@ class CORE_EXPORT QgsMultiLineStringV2: public QgsMultiCurveV2
     /** Adds a geometry and takes ownership. Returns true in case of success*/
     virtual bool addGeometry( QgsAbstractGeometryV2* g ) override;
 
-    /** Returns the geometry converted to QgsMultiCurveV2*/
+    /** Returns the geometry converted to the more generic curve type QgsMultiCurveV2
+    @return the converted geometry. Caller takes ownership*/
     QgsAbstractGeometryV2* toCurveType() const override;
 
   protected:
diff --git a/src/core/geometry/qgsmultipolygonv2.h b/src/core/geometry/qgsmultipolygonv2.h
index 176dfd14e47..e6bb7585083 100644
--- a/src/core/geometry/qgsmultipolygonv2.h
+++ b/src/core/geometry/qgsmultipolygonv2.h
@@ -43,7 +43,8 @@ class CORE_EXPORT QgsMultiPolygonV2: public QgsMultiSurfaceV2
     /** Adds a geometry and takes ownership. Returns true in case of success*/
     virtual bool addGeometry( QgsAbstractGeometryV2* g ) override;
 
-    /** Returns the geometry converted to QgsMultiSurfaceV2*/
+    /** Returns the geometry converted to the more generic curve type QgsMultiSurfaceV2
+    @return the converted geometry. Caller takes ownership*/
     QgsAbstractGeometryV2* toCurveType() const override;
 
   protected:
diff --git a/src/core/geometry/qgspolygonv2.h b/src/core/geometry/qgspolygonv2.h
index 1f0c125f270..031a0428a28 100644
--- a/src/core/geometry/qgspolygonv2.h
+++ b/src/core/geometry/qgspolygonv2.h
@@ -50,7 +50,8 @@ class CORE_EXPORT QgsPolygonV2: public QgsCurvePolygonV2
 
     QgsPolygonV2* surfaceToPolygon() const override;
 
-    /** Returns the geometry converted to QgsCurvePolygonV2*/
+    /** Returns the geometry converted to the more generic curve type QgsCurvePolygonV2
+     @return the converted geometry. Caller takes ownership*/
     QgsAbstractGeometryV2* toCurveType() const override;
 
     void addInteriorRing( QgsCurveV2* ring ) override;
diff --git a/src/core/qgsvectorlayereditbuffer.h b/src/core/qgsvectorlayereditbuffer.h
index 8f2abb8e2bf..8f52849b6ca 100644
--- a/src/core/qgsvectorlayereditbuffer.h
+++ b/src/core/qgsvectorlayereditbuffer.h
@@ -156,8 +156,6 @@ class CORE_EXPORT QgsVectorLayerEditBuffer : public QObject
 
     void updateLayerFields();
 
-    QgsAbstractGeometryV2* outputGeometry( QgsAbstractGeometryV2* geom ) const;
-
   protected:
     QgsVectorLayer* L;
     friend class QgsVectorLayer;
@@ -191,6 +189,8 @@ class CORE_EXPORT QgsVectorLayerEditBuffer : public QObject
     /** Changed geometries which are not commited. */
     QgsGeometryMap mChangedGeometries;
 
+  private:
+    QgsAbstractGeometryV2* outputGeometry( QgsAbstractGeometryV2* geom ) const;
 };
 
 #endif // QGSVECTORLAYEREDITBUFFER_H