diff --git a/.gitmodules b/.gitmodules
index 367abb8..61d9cee 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -77,3 +77,4 @@
 [submodule "moonray/materialx_shaders"]
 	path = moonray/materialx_shaders
 	url = ../materialx_shaders
+	branch = main
diff --git a/moonray/materialx_shaders b/moonray/materialx_shaders
index 9b83c00..4079004 160000
--- a/moonray/materialx_shaders
+++ b/moonray/materialx_shaders
@@ -1 +1 @@
-Subproject commit 9b83c0051418e09869c14e2a86abe788a7ab7dca
+Subproject commit 40790043f7a9ecdf4b4fcc9471c77a9fd7556f8c