diff --git a/src/osmo_gsm_tester/core/suite.py b/src/osmo_gsm_tester/core/suite.py
index a1d068e..3860d19 100644
--- a/src/osmo_gsm_tester/core/suite.py
+++ b/src/osmo_gsm_tester/core/suite.py
@@ -80,7 +80,7 @@
     def __init__(self, trial, suite_scenario_str, suite_definition, scenarios=[]):
         super().__init__(log.C_TST, suite_scenario_str)
         self.start_timestamp = None
-        self.duration = None
+        self.duration = 0
         self.reserved_resources = None
         self._resource_requirements = None
         self._resource_modifiers = None