diff --git a/src/slic3r/GUI/Jobs/UIThreadWorker.hpp b/src/slic3r/GUI/Jobs/UIThreadWorker.hpp
index b8ac914fd7..610d205cf9 100644
--- a/src/slic3r/GUI/Jobs/UIThreadWorker.hpp
+++ b/src/slic3r/GUI/Jobs/UIThreadWorker.hpp
@@ -35,10 +35,14 @@ class UIThreadWorker : public Worker, private Job::Ctl {
                 eptr= std::current_exception();
             }
 
-            m_running = false;
-
             job->finalize(m_canceled, eptr);
 
+            // Unhandled exceptions are rethrown without mercy.
+            if (eptr)
+                std::rethrow_exception(eptr);
+
+            m_running = false;
+
             m_canceled = false;
         }
     }