diff --git a/src/wormhole/blocking/transcribe.py b/src/wormhole/blocking/transcribe.py
index 167fd9f..bd83ea9 100644
--- a/src/wormhole/blocking/transcribe.py
+++ b/src/wormhole/blocking/transcribe.py
@@ -293,7 +293,6 @@ class Wormhole:
                                    idSymmetric=to_bytes(self._appid))
         self.msg1 = self.sp.start()
 
-    @close_on_error
     def derive_key(self, purpose, length=SecretBox.KEY_SIZE):
         if not isinstance(purpose, type(u"")): raise TypeError(type(purpose))
         return HKDF(self.key, length, CTXinfo=to_bytes(purpose))
diff --git a/src/wormhole/twisted/transcribe.py b/src/wormhole/twisted/transcribe.py
index e71cd42..6ea9e41 100644
--- a/src/wormhole/twisted/transcribe.py
+++ b/src/wormhole/twisted/transcribe.py
@@ -331,7 +331,6 @@ class Wormhole:
         self.msg1 = d["msg1"].decode("hex")
         return self
 
-    #@close_on_error # XXX
     def derive_key(self, purpose, length=SecretBox.KEY_SIZE):
         if not isinstance(purpose, type(u"")): raise TypeError(type(purpose))
         if self.key is None: