diff --git a/python/core/auto_generated/geometry/qgsgeometry.sip.in b/python/core/auto_generated/geometry/qgsgeometry.sip.in
index 7f87553c854..a602f6d25f4 100644
--- a/python/core/auto_generated/geometry/qgsgeometry.sip.in
+++ b/python/core/auto_generated/geometry/qgsgeometry.sip.in
@@ -133,6 +133,12 @@ Sets the underlying geometry store. Ownership of geometry is transferred.
 
    In QGIS 2.x this method was named setGeometry().
 
+.. note::
+
+   This method is deprecated for usage in Python and will be removed from Python bindings with QGIS 4.
+   Using this method will confuse Python's memory management and type information system.
+   Better create a new QgsGeometry object instead.
+
 .. seealso:: :py:func:`get`
 
 .. seealso:: :py:func:`constGet`
diff --git a/src/core/geometry/qgsgeometry.h b/src/core/geometry/qgsgeometry.h
index 787801119bc..919b8103d33 100644
--- a/src/core/geometry/qgsgeometry.h
+++ b/src/core/geometry/qgsgeometry.h
@@ -196,6 +196,9 @@ class CORE_EXPORT QgsGeometry
      * Sets the underlying geometry store. Ownership of geometry is transferred.
      *
      * \note In QGIS 2.x this method was named setGeometry().
+     * \note This method is deprecated for usage in Python and will be removed from Python bindings with QGIS 4.
+     *       Using this method will confuse Python's memory management and type information system.
+     *       Better create a new QgsGeometry object instead.
      *
      * \see get()
      * \see constGet()