diff -Naur gshutdown-0.2.old/src/gui.c gshutdown-0.2/src/gui.c
--- gshutdown-0.2.old/src/gui.c	2014-08-06 06:41:05.789103128 +0200
+++ gshutdown-0.2/src/gui.c	2014-08-06 06:41:46.573613266 +0200
@@ -725,7 +725,7 @@
                                     GTK_DIALOG_MODAL,
                                     GTK_MESSAGE_QUESTION,
                                     GTK_BUTTONS_YES_NO,
-                                    message);
+                                    "%s", message);
 
     response = gtk_dialog_run(GTK_DIALOG(dialog));
     gtk_widget_destroy(GTK_WIDGET(dialog));
@@ -759,7 +759,7 @@
                                         GTK_DIALOG_MODAL,
                                         GTK_MESSAGE_ERROR,
                                         GTK_BUTTONS_OK,
-                                        message);
+                                        "%s", message);
         gtk_dialog_run(GTK_DIALOG(dialog));
         gtk_widget_destroy(dialog);