diff --git a/src/plugins/plugin_xep_0115.py b/src/plugins/plugin_xep_0115.py
index 19dc65f6..8db777a9 100755
--- a/src/plugins/plugin_xep_0115.py
+++ b/src/plugins/plugin_xep_0115.py
@@ -61,10 +61,12 @@ class XEP_0115(object):
         return XEP_0115_handler(self, profile)
 
     def _checkHash(self, disco_d, profile):
+        client = self.host.getClient(profile)
+        client.caps_optimize = None
+
         if XEP_0115.cap_hash is None:
             disco_d.addCallback(lambda dummy: self.host.hasFeature(NS_CAPS_OPTIMIZE, profile_key=profile))
             def updateOptimize(optimize):
-                client = self.host.getClient(profile)
                 client.caps_optimize = optimize
                 if optimize:
                     info(_("Caps optimisation enabled"))