diff --git a/src/pyj/iframe_comm.pyj b/src/pyj/iframe_comm.pyj
index 35c178c298..6d22b13d6f 100644
--- a/src/pyj/iframe_comm.pyj
+++ b/src/pyj/iframe_comm.pyj
@@ -135,11 +135,13 @@ class IframeWrapper:
                 print('Could not process message from iframe:')
                 console.log(e)
                 return
+        if not data.action:
+            return
         func = self.handlers[data.action]
         if func:
             func(data)
         else:
-            print('Unknown action in message from iframe to parent: ' + data.action)
+            print('Unknown action in message from iframe to parent:', data.action)
 
     def on_iframe_ready(self, data):
         self.messenger.reset()
diff --git a/src/pyj/read_book/iframe.pyj b/src/pyj/read_book/iframe.pyj
index b2ca326552..cdd63cdd1f 100644
--- a/src/pyj/read_book/iframe.pyj
+++ b/src/pyj/read_book/iframe.pyj
@@ -71,7 +71,6 @@ class IframeBoss:
         window.navigator.epubReadingSystem = EPUBReadingSystem()
         self.last_cfi = None
         self.replace_history_on_next_cfi_update = True
-        self.encrypted_communications = False
         self.blob_url_map = {}
         self.resource_urls = {}
         self.content_ready = False