diff --git a/leenkx/blender/lnx/material/make_finalize.py b/leenkx/blender/lnx/material/make_finalize.py
index 9760e3c..336980f 100644
--- a/leenkx/blender/lnx/material/make_finalize.py
+++ b/leenkx/blender/lnx/material/make_finalize.py
@@ -78,7 +78,7 @@ def make(con_mesh: ShaderContext):
     if export_wpos:
         vert.add_uniform('mat4 W', '_worldMatrix')
         vert.add_out('vec3 wposition')
-        vert.write('wposition = vec4(W * spos).xyz;')
+        vert.write_attrib('wposition = vec4(W * spos).xyz;')
     elif write_wpos:
         vert.add_uniform('mat4 W', '_worldMatrix')
         vert.write_attrib('vec3 wposition = vec4(W * spos).xyz;')