diff --git a/fast64_internal/f3d/f3d_writer.py b/fast64_internal/f3d/f3d_writer.py
index 056d4131b..a0edcd0bf 100644
--- a/fast64_internal/f3d/f3d_writer.py
+++ b/fast64_internal/f3d/f3d_writer.py
@@ -334,14 +334,21 @@ def saveStaticModel(
 
     # checkForF3DMaterial(obj)
 
-    facesByMat = {}
+    faces_by_mat = {}
     for face in obj.data.loop_triangles:
-        if face.material_index not in facesByMat:
-            facesByMat[face.material_index] = []
-        facesByMat[face.material_index].append(face)
+        if face.material_index not in faces_by_mat:
+            faces_by_mat[face.material_index] = []
+        faces_by_mat[face.material_index].append(face)
+
+    # sort by material slot
+    faces_by_mat = {
+        mat_index: faces_by_mat[mat_index]
+        for mat_index, _ in enumerate(obj.material_slots)
+        if mat_index in faces_by_mat
+    }
 
     fMeshes = {}
-    for material_index, faces in facesByMat.items():
+    for material_index, faces in faces_by_mat.items():
         material = obj.material_slots[material_index].material
 
         if drawLayerField is not None and material.mat_ver > 3: