diff --git a/reactos/win32ss/user/ntuser/desktop.c b/reactos/win32ss/user/ntuser/desktop.c
index dfa993ea9f8..566af46425e 100644
--- a/reactos/win32ss/user/ntuser/desktop.c
+++ b/reactos/win32ss/user/ntuser/desktop.c
@@ -1632,6 +1632,12 @@ NtUserSwitchDesktop(HDESK hdesk)
       RETURN(FALSE);
    }
 
+   if (PsGetCurrentProcessSessionId() != pdesk->rpwinstaParent->dwSessionId)
+   {
+      ERR("NtUserSwitchDesktop called for a desktop of a different session\n");
+      RETURN(FALSE);  
+   }
+
    if(pdesk == gpdeskInputDesktop)
    {
        WARN("NtUserSwitchDesktop called for active desktop\n");
diff --git a/reactos/win32ss/user/ntuser/winsta.c b/reactos/win32ss/user/ntuser/winsta.c
index 3056fc3d5bf..315fdb5da54 100644
--- a/reactos/win32ss/user/ntuser/winsta.c
+++ b/reactos/win32ss/user/ntuser/winsta.c
@@ -432,6 +432,7 @@ NtUserCreateWindowStation(
    Status = RtlCreateAtomTable(37, &WindowStationObject->AtomTable);
    WindowStationObject->SystemMenuTemplate = (HANDLE)0;
    WindowStationObject->Name = WindowStationName;
+   WindowStationObject->dwSessionId = NtCurrentPeb()->SessionId;
 
    if (InputWindowStation == NULL)
    {
diff --git a/reactos/win32ss/user/ntuser/winsta.h b/reactos/win32ss/user/ntuser/winsta.h
index f2d0fba2ea6..4b20fc6f251 100644
--- a/reactos/win32ss/user/ntuser/winsta.h
+++ b/reactos/win32ss/user/ntuser/winsta.h
@@ -9,6 +9,8 @@
 
 typedef struct _WINSTATION_OBJECT
 {
+    DWORD dwSessionId;
+
     KSPIN_LOCK Lock;
     UNICODE_STRING Name;
     LIST_ENTRY DesktopListHead;