diff --git a/build/tools/roomservice.py b/build/tools/roomservice.py
index 6347f9f..5020915 100755
--- a/build/tools/roomservice.py
+++ b/build/tools/roomservice.py
@@ -140,7 +140,7 @@
         if localpath.get("path") == projectpath:
             return True
 
-    ## Search in main manifest, too
+    # Search in main manifest, too
     try:
         lm = ElementTree.parse(".repo/manifest.xml")
         lm = lm.getroot()
@@ -151,6 +151,17 @@
         if localpath.get("path") == projectpath:
             return True
 
+    # ... and don't forget the lineage snippet
+    try:
+        lm = ElementTree.parse(".repo/manifests/snippets/cm.xml")
+        lm = lm.getroot()
+    except:
+        lm = ElementTree.Element("manifest")
+
+    for localpath in lm.findall("project"):
+        if localpath.get("path") == projectpath:
+            return True
+
     return False
 
 def add_to_manifest(repositories, fallback_branch = None):