diff --git a/src/opt/optsmt.cpp b/src/opt/optsmt.cpp
index 4686910c8..8428f03ab 100644
--- a/src/opt/optsmt.cpp
+++ b/src/opt/optsmt.cpp
@@ -51,6 +51,7 @@ namespace opt {
 
 
     void optsmt::set_cancel(bool f) {
+        TRACE("opt", tout << "set cancel: " << f << "\n";);
         m_cancel = f;
     }