diff --git a/thorlcr/activities/when/thwhenslave.cpp b/thorlcr/activities/when/thwhenslave.cpp
index 679234da6bb..c77fd9383f5 100644
--- a/thorlcr/activities/when/thwhenslave.cpp
+++ b/thorlcr/activities/when/thwhenslave.cpp
@@ -92,6 +92,11 @@ class CWhenSlaveActivity : public CDependencyExecutorSlaveActivity
                 abortSoon = true;
         }
     }
+    virtual void start() override
+    {
+        ActivityTimer s(slaveTimerStats, timeActivities);
+        PARENT::start();
+    }
     virtual bool isGrouped() const override { return input->isGrouped(); }
     CATCH_NEXTROW()
     {