diff --git a/vncviewer/CConn.cxx b/vncviewer/CConn.cxx
index addc30d..2e97ec2 100644
--- a/vncviewer/CConn.cxx
+++ b/vncviewer/CConn.cxx
@@ -110,7 +110,8 @@
       vlog.info(_("connected to host %s port %d"), serverHost, serverPort);
     } catch (rdr::Exception& e) {
       vlog.error("%s", e.str());
-      fl_alert("%s", e.str());
+      if (alertOnFatalError)
+        fl_alert("%s", e.str());
       exit_vncviewer();
       return;
     }