diff --git a/.mergesources.yml b/.mergesources.yml
new file mode 100644
index 0000000..29bd1dd
--- /dev/null
+++ b/.mergesources.yml
@@ -0,0 +1,11 @@
+# Data source for the "arb" svn merge tool (see http://github.com/sminnee/arborist).
+# Keeps track of all opensource branches of submodules 
+# that could be merged back to the current submodule paths.
+trunk:
+  .: /open/phpinstaller/trunk
+  sapphire: /open/modules/sapphire/trunk
+  cms: /open/modules/cms/trunk
+2.4:
+  .: /open/phpinstaller/branches/2.4
+  sapphire: /open/modules/sapphire/branches/2.4
+  cms: /open/modules/cms/branches/2.4
\ No newline at end of file