diff --git a/src/mcp/server/auth/provider.py b/src/mcp/server/auth/provider.py
index 4ce11375..bb47c195 100644
--- a/src/mcp/server/auth/provider.py
+++ b/src/mcp/server/auth/provider.py
@@ -68,6 +68,7 @@ AuthorizationErrorCode = Literal[
     "invalid_scope",
     "server_error",
     "temporarily_unavailable",
+    "invalid_target",
 ]