diff --git a/src/bonsai/bonsai/bim/module/model/wall.py b/src/bonsai/bonsai/bim/module/model/wall.py
index c43bf2a7d2..0bedb86fc6 100644
--- a/src/bonsai/bonsai/bim/module/model/wall.py
+++ b/src/bonsai/bonsai/bim/module/model/wall.py
@@ -1364,7 +1364,7 @@ class DumbWallJoiner:
                         tool.Ifc.get(), opening.Representation, exclude=["IfcGeometricRepresentationContext"]
                     )
 
-                rel.RelatedBuildingElement = element2
+                rel.RelatingOpeningElement = new_opening
 
                 # Remove the old opening
                 ifcopenshell.api.feature.remove_feature(tool.Ifc.get(), feature=opening)
diff --git a/src/bonsai/test/bim/feature/model.feature b/src/bonsai/test/bim/feature/model.feature
index bfae14c6f6..1cab957837 100644
--- a/src/bonsai/test/bim/feature/model.feature
+++ b/src/bonsai/test/bim/feature/model.feature
@@ -285,6 +285,7 @@ Scenario: Split a wall which has a flipped door
     And the object "IfcWall/Wall" is selected
     And I press "bim.hotkey(hotkey='S_K')"
     Then the object "IfcDoor/Door" is at "8.01,0.1,0"
+    And the object "IfcWall/Wall.001" is filled by "IfcDoor/Door"
 
 Scenario: Offset walls
     Given an empty IFC project