diff --git a/confluent/httpapi.py b/confluent/httpapi.py
index 357fe81e..d30a7d74 100644
--- a/confluent/httpapi.py
+++ b/confluent/httpapi.py
@@ -217,12 +217,18 @@ def resourcehandler(env, start_response):
             for idx in xrange(0, len(querydict['keys']), 2):
                 input += chr(int(querydict['keys'][idx:idx+2],16))
             sessid = querydict['session']
+            if sessid not in consolesessions:
+                start_response('400 Expired Session', headers)
+                return
             consolesessions[sessid]['expiry'] = time.time() + 90
             consolesessions[sessid]['session'].write(input)
             start_response('200 OK', headers)
             return # client has requests to send or receive, not both...
         else: #no keys, but a session, means it's hooking to receive data
             sessid = querydict['session']
+            if sessid not in consolesessions:
+                start_response('400 Expired Session', headers)
+                return
             consolesessions[sessid]['expiry'] = time.time() + 90
             outdata = consolesessions[sessid]['session'].get_next_output(timeout=45)
             try: