diff --git a/credentialz/credentialz.proto b/credentialz/credentialz.proto
index e12593c..b67721f 100644
--- a/credentialz/credentialz.proto
+++ b/credentialz/credentialz.proto
@@ -237,6 +237,15 @@ message RotateAccountCredentialsRequest {
     PasswordRequest password = 3;
     FinalizeRequest finalize = 4;
   }
+
+  // If set to `true` the requested operation will succeed even if the specified
+  // `version` or `credential` is already in use (is not unique).
+  // If set to `false` the requested operation will fail and the streaming RPC
+  // will be closed with the `ALREADY_EXISTS` gRPC error if the specified
+  // version` is already in use (is not unique).
+  // It is a no-op for the `finalize_rotation` request.
+  bool force_overwrite = 5;
+
 }
 
 // RotateAccountCredentialsResponse is the response to