diff --git a/h11/__init__.py b/h11/__init__.py
index 989e92c..7a22c83 100644
--- a/h11/__init__.py
+++ b/h11/__init__.py
@@ -51,12 +51,14 @@
     "DONE",
     "ERROR",
     "IDLE",
+    "MIGHT_SWITCH_PROTOCOL",
     "MUST_CLOSE",
     "SEND_BODY",
     "SEND_RESPONSE",
     "SERVER",
     "SWITCHED_PROTOCOL",
-    "ProtocolError",
     "LocalProtocolError",
+    "ProtocolError",
     "RemoteProtocolError",
+    "PRODUCT_ID",
 )