Index: /trunk/src/VBox/Frontends/VBoxManage/VBoxManageGuestCtrl.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VBoxManage/VBoxManageGuestCtrl.cpp	(revision 57592)
+++ /trunk/src/VBox/Frontends/VBoxManage/VBoxManageGuestCtrl.cpp	(revision 57593)
@@ -3726,5 +3726,5 @@
     }
 
-    if (fSeenListArg)
+    if (!fSeenListArg)
         return errorSyntaxEx(USAGE_GUESTCONTROL, USAGE_GSTCTRL_LIST, "Missing list name");
     Assert(fListAll || fListSessions);