diff --git a/clang/lib/AST/CommentCommandTraits.cpp b/clang/lib/AST/CommentCommandTraits.cpp
index ba0aa9a..e7e40fd 100644
--- a/clang/lib/AST/CommentCommandTraits.cpp
+++ b/clang/lib/AST/CommentCommandTraits.cpp
@@ -40,6 +40,7 @@
   CommandInfo *Info = new (Allocator) CommandInfo();
   Info->Name = Name;
   Info->ID = NextID++;
+  Info->IsUnknownCommand = true;
 
   RegisteredCommands.push_back(Info);