diff --git a/build/tools/roomservice.py b/build/tools/roomservice.py
index a0a6bd77..8c55c518 100755
--- a/build/tools/roomservice.py
+++ b/build/tools/roomservice.py
@@ -188,7 +188,7 @@ def add_to_manifest(repositories):
                 project.attrib["remote"] = repo_remote
                 project.attrib["clone-depth"] = "1"
                 del project.attrib["revision"]
-        if project.attrib["revision"] == get_default_revision():
+        if project.attrib.get("revision", None) == get_default_revision():
             del project.attrib["revision"]
         print("Adding dependency: %s -> %s" % (project.attrib["name"], project.attrib["path"]))
         lm.append(project)