diff --git a/reactos/win32ss/w32ksvc.h b/reactos/win32ss/w32ksvc.h
index 3b6db971587..f0d97187e17 100644
--- a/reactos/win32ss/w32ksvc.h
+++ b/reactos/win32ss/w32ksvc.h
@@ -485,7 +485,7 @@ SVC_(UserPostMessage, 4)
 SVC_(UserPostThreadMessage, 4)
 SVC_(UserPrintWindow, 3)
 SVC_(UserProcessConnect, 3)
-SVC_(UserQueryInformationThread, 5)
+SVC_(UserQueryInformationThread, 4)
 SVC_(UserQueryInputContext, 2)
 SVC_(UserQuerySendMessage, 1)
 SVC_(UserQueryUserCounters, 5)