diff --git a/.gitmodules b/.gitmodules
index 34bab50f80f..6fe3acafafa 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -5,7 +5,7 @@
 [submodule "external/mono"]
 	path = external/mono
 	url = https://github.com/mono/mono.git
-	branch = 2017-04
+	branch = d15-3
 [submodule "external/mxe"]
 	path = external/mxe
 	url = https://github.com/xamarin/mxe.git