diff --git a/reactos/subsystems/win32/win32k/eng/surface.c b/reactos/subsystems/win32/win32k/eng/surface.c
index 317cf0497bb..9a0a55689ff 100644
--- a/reactos/subsystems/win32/win32k/eng/surface.c
+++ b/reactos/subsystems/win32/win32k/eng/surface.c
@@ -563,7 +563,7 @@ EngLockSurface(IN HSURF Surface)
  * @implemented
  */
 VOID STDCALL
-NtGdiEngUnLockSurface(IN SURFOBJ *Surface)
+NtGdiEngUnlockSurface(IN SURFOBJ *Surface)
 {
     EngUnlockSurface(Surface);
 }