diff --git a/reactos/include/win32k/ntuser.h b/reactos/include/win32k/ntuser.h
index e7ac9e8335a..f95e001345c 100644
--- a/reactos/include/win32k/ntuser.h
+++ b/reactos/include/win32k/ntuser.h
@@ -1,6 +1,11 @@
 #ifndef __WIN32K_NTUSER_H
 #define __WIN32K_NTUSER_H
 
+NTSTATUS
+STDCALL
+NtUserAcquireOrReleaseInputOwnership(
+  BOOLEAN Release);
+
 DWORD
 STDCALL
 NtUserActivateKeyboardLayout(