diff --git a/src/Mod/Arch/exportIFC.py b/src/Mod/Arch/exportIFC.py
index 0ba8256c3d..3f19602df9 100644
--- a/src/Mod/Arch/exportIFC.py
+++ b/src/Mod/Arch/exportIFC.py
@@ -972,7 +972,8 @@ def export(exportList,filename,colors=None,preferences=None):
                 if not(Draft.getType(FreeCAD.ActiveDocument.getObject(k)) in ["Site","Building","Floor","BuildingPart"]):
                     untreated.append(v)
                 elif Draft.getType(FreeCAD.ActiveDocument.getObject(k)) == "BuildingPart":
-                    if not(FreeCAD.ActiveDocument.getObject(k).IfcType in ["Building","Building Storey","Site","Space","Undefined"]):
+                    if not(FreeCAD.ActiveDocument.getObject(k).IfcType in ["Building","Building Storey","Site","Space"]):
+                        # if ifc type is "Undefined" the object is added to untreated
                         untreated.append(v)
     if untreated:
         if not defaulthost: