diff --git a/src/blenderbim/blenderbim/bim/module/model/wall.py b/src/blenderbim/blenderbim/bim/module/model/wall.py
index 83cd8c46b5..6c309d5999 100644
--- a/src/blenderbim/blenderbim/bim/module/model/wall.py
+++ b/src/blenderbim/blenderbim/bim/module/model/wall.py
@@ -611,7 +611,7 @@ class DumbWallGenerator:
             "geometry.add_wall_representation",
             tool.Ifc.get(),
             context=self.body_context,
-            thickness=self.layers["thickness"],
+            thickness=self.layers["thickness"] * 1/cos(self.x_angle), #1/cos(self.x_angle) maintains the correct MaterialLayer thickness upon rotation
             offset=self.layers["offset"],
             length=self.length,
             height=self.height,
@@ -1092,7 +1092,7 @@ class DumbWallJoiner:
             height=height,
             x_angle=x_angle,
             offset=layers["offset"],
-            thickness=layers["thickness"],
+            thickness=layers["thickness"] * 1/cos(x_angle), #1/cos(x_angle) maintains the correct MaterialLayer thickness upon rotation
             clippings=self.clippings,
             booleans=tool.Model.get_manual_booleans(element),
         )