diff --git a/reactos/boot/bootdata/hivesys.inf b/reactos/boot/bootdata/hivesys.inf
index 1b7e10d9673..47a7c8c76f7 100644
--- a/reactos/boot/bootdata/hivesys.inf
+++ b/reactos/boot/bootdata/hivesys.inf
@@ -1253,6 +1253,9 @@ HKLM,"SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems","Posix",0x000
 HKLM,"SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems","Required",0x00010000,"Debug","Windows"
 HKLM,"SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems","Windows",0x00020000,"%SystemRoot%\system32\csrss.exe ObjectDirectory=\Windows SharedSection=1024,12288,512 Windows=On SubSystemType=Windows ServerDll=basesrv,1 ServerDll=winsrv:UserServerDllInitialization,3 ServerDll=winsrv:ConServerDllInitialization,2 ProfileControl=Off MaxRequestThreads=16"
 
+; App Compat -- Disable on ReactOS
+HKLM,"SYSTEM\CurrentControlSet\Control\Session Manager\AppCompatibility","DisableAppCompat",0x00010003, 0x00000001
+
 ; WOW Support
 HKLM,"SYSTEM\CurrentControlSet\Control\Wow","",0x00000000,""