diff --git a/libcxx/.arcconfig b/libcxx/.arcconfig
index c96fbc1b4e6c..b7486508bc1e 100644
--- a/libcxx/.arcconfig
+++ b/libcxx/.arcconfig
@@ -1,4 +1,4 @@
 {
-  "project_id" : "libcxx",
+  "repository.callsign" : "CXX",
   "conduit_uri" : "https://reviews.llvm.org/"
 }