diff --git a/src/osmo_gsm_tester/ofono_client.py b/src/osmo_gsm_tester/ofono_client.py
index 9425671..c5ae1ff 100644
--- a/src/osmo_gsm_tester/ofono_client.py
+++ b/src/osmo_gsm_tester/ofono_client.py
@@ -98,11 +98,14 @@
         # { I_SMS: ( token1, token2, ... ), }
         self.connected_signals = util.listdict()
 
-    def __del__(self):
+    def cleanup(self):
         self.unwatch_interfaces()
         for interface_name in list(self.connected_signals.keys()):
             self.remove_signals(interface_name)
 
+    def __del__(self):
+        self.cleanup()
+
     def get_new_dbus_obj(self):
         return systembus_get(self.modem_path)
 
@@ -268,6 +271,10 @@
             }
         self.dbus.watch_interfaces()
 
+    def cleanup(self):
+        self.dbus.cleanup()
+        self.dbus = None
+
     def properties(self, *args, **kwargs):
         '''Return a dict of properties on this modem. For the actual arguments,
         see ModemDbusInteraction.properties(), which this function calls.  The
diff --git a/src/osmo_gsm_tester/suite.py b/src/osmo_gsm_tester/suite.py
index 6a1796f..75c461e 100644
--- a/src/osmo_gsm_tester/suite.py
+++ b/src/osmo_gsm_tester/suite.py
@@ -174,6 +174,7 @@
     trial = None
     resources_pool = None
     reserved_resources = None
+    objects_to_clean_up = None
     _resource_requirements = None
     _config = None
     _processes = None
@@ -186,6 +187,16 @@
         self.set_log_category(log.C_TST)
         self.resources_pool = resource.ResourcesPool()
 
+    def register_for_cleanup(self, *obj):
+        assert all([hasattr(o, 'cleanup') for o in obj])
+        self.objects_to_clean_up = self.objects_to_clean_up or []
+        self.objects_to_clean_up.extend(obj)
+
+    def objects_cleanup(self):
+        while self.objects_to_clean_up:
+            obj = self.objects_to_clean_up.pop()
+            obj.cleanup()
+
     def mark_start(self):
         self.tests = []
         self.start_timestamp = time.time()
@@ -248,6 +259,7 @@
             # base exception is raised. Make sure to stop processes in this
             # finally section. Resources are automatically freed with 'atexit'.
             self.stop_processes()
+            self.objects_cleanup()
             self.free_resources()
         event_loop.unregister_poll_func(self.poll)
         self.duration = time.time() - self.start_timestamp
@@ -306,7 +318,11 @@
         return bts_obj(self, self.reserved_resources.get(resource.R_BTS))
 
     def modem(self):
-        return modem_obj(self.reserved_resources.get(resource.R_MODEM))
+        conf = self.reserved_resources.get(resource.R_MODEM)
+        self.dbg('create Modem object', conf=conf)
+        modem = ofono_client.Modem(conf)
+        self.register_for_cleanup(modem)
+        return modem
 
     def modems(self, count):
         l = []
@@ -398,8 +414,4 @@
         raise RuntimeError('No such BTS type is defined: %r' % bts_type)
     return bts_class(suite_run, conf)
 
-def modem_obj(conf):
-    log.dbg(None, None, 'create Modem object', conf=conf)
-    return ofono_client.Modem(conf)
-
 # vim: expandtab tabstop=4 shiftwidth=4