diff --git a/src/TNL/Solvers/SolverMonitor.h b/src/TNL/Solvers/SolverMonitor.h
index cbd8bef7240f01a0878dd53e2b03c6179b284e53..46911415f469aa16f52ac683607e598e2736cd2e 100644
--- a/src/TNL/Solvers/SolverMonitor.h
+++ b/src/TNL/Solvers/SolverMonitor.h
@@ -24,7 +24,8 @@ class SolverMonitor
 
    SolverMonitor()
       : timeout_milliseconds(500),
-        stopped(true)
+        stopped(true),
+        timer(nullptr)
    {};
 
    ~SolverMonitor() {};