diff --git a/system_api/dbus/cryptohome/auth_factor.proto b/system_api/dbus/cryptohome/auth_factor.proto
index 25dea98..6e0f66e 100644
--- a/system_api/dbus/cryptohome/auth_factor.proto
+++ b/system_api/dbus/cryptohome/auth_factor.proto
@@ -31,10 +31,10 @@
   PURPOSE_UNSPECIFIED = 0;
   // For adding a new auth factor. Usually it indicates PrepareAsynAuthFactor()
   // runs an auth factor enrollment process (based on user input collection).
-  ADD_AUTH_FACTOR = 1;
+  PURPOSE_ADD_AUTH_FACTOR = 1;
   // For authenticating an existing async auth factor. Usually this indicates
   // PrepareAsyncAuthFactor() runs an user input collection process.
-  AUTHENTICATE_AUTH_FACTOR = 2;
+  PURPOSE_AUTHENTICATE_AUTH_FACTOR = 2;
 }
 
 // Cryptographic signature algorithm type for smart card requests. Used with