diff --git a/AMBuildScript b/AMBuildScript
index 6d9761c6..5b989729 100644
--- a/AMBuildScript
+++ b/AMBuildScript
@@ -114,6 +114,8 @@ class SMConfig(object):
       self.mms_root = builder.options.mms_path
     else:
       self.mms_root = ResolveEnvPath('MMSOURCE110', 'mmsource-1.10')
+      if not self.mms_root:
+        self.mms_root = ResolveEnvPath('MMSOURCE_DEV', 'metamod-source')
       if not self.mms_root:
         self.mms_root = ResolveEnvPath('MMSOURCE_DEV', 'mmsource-central')