diff --git a/test/regression/settings.py b/test/regression/settings.py
index eca2e79fd..77570ff52 100644
--- a/test/regression/settings.py
+++ b/test/regression/settings.py
@@ -60,9 +60,9 @@ files_to_ignore = ["pond.0.ply"]
 # File extensions are case insensitive
 # -------------------------------------------------------------------------------
 exclude_extensions = [
-    ".lws", ".assbin", ".assxml", ".txt", ".md",
+    ".assbin", ".assxml", ".txt", ".md",
     ".jpeg", ".jpg", ".png", ".gif", ".tga", ".bmp",
-    ".skeleton", ".skeleton.xml", ".license"
+    ".skeleton", ".skeleton.xml", ".license", ".mtl", ".material"
 ]
 
 # -------------------------------------------------------------------------------