diff --git a/src/Mod/Arch/ArchWall.py b/src/Mod/Arch/ArchWall.py
index f09b717d22..17a41a8c22 100644
--- a/src/Mod/Arch/ArchWall.py
+++ b/src/Mod/Arch/ArchWall.py
@@ -1054,8 +1054,9 @@ class _Wall(ArchComponent.Component):
                                     obj.Base.End = p2
                                 elif Draft.getType(obj.Base) == "Sketcher::SketchObject":
                                     try:
-                                        obj.Base.movePoint(0,2,p2,0)
-                                    except Exception:
+                                        obj.Base.recompute() # Fix for the 'GeoId index out range' error.
+                                        obj.Base.movePoint(0, 2, obj.Base.Placement.inverse().multVec(p2))
+                                    except Exception: # This 'GeoId index out range' error should no longer occur.
                                         print("Debug: The base sketch of this wall could not be changed, because the sketch has not been edited yet in this session (this is a bug in FreeCAD). Try entering and exiting edit mode in this sketch first, and then changing the wall length should work.")
                                 else:
                                     FreeCAD.Console.PrintError(translate("Arch","Error: Unable to modify the base object of this wall")+"\n")