diff --git a/runtime/vm/object_id_ring.h b/runtime/vm/object_id_ring.h
index d94965c..07bc854 100644
--- a/runtime/vm/object_id_ring.h
+++ b/runtime/vm/object_id_ring.h
@@ -14,11 +14,11 @@
 class ObjectPointerVisitor;
 class JSONStream;
 
-// A ring buffer of object pointers that have been given an id. An object
-// may be pointed to by multiple ids. Objects contained in the ring will
-// be preserved across scavenges but not old space collections.
-// When the ring buffer wraps around older objects will be replaced and their
-// ids will be invalidated.
+// A ring buffer of object pointers that have been given temporary Service IDs.
+// An object may be pointed to by multiple IDs. The objects associated with the
+// pointers in the ring will be preserved across garbage collections. When the
+// ring buffer wraps around, older objects will be replaced and their IDs will
+// become expired.
 class ObjectIdRing {
  public:
   enum LookupResult {