diff --git a/reactos/subsystems/win32/win32k/ntuser/ntstubs.c b/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
index dd8bd66d657..e7d573b7dc3 100644
--- a/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
+++ b/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
@@ -309,6 +309,7 @@ NtUserGetMouseMovePointsEx(
 
    if ((cbSize != sizeof(MOUSEMOVEPOINT)) || (nBufPoints < 0) || (nBufPoints > 64))
    {
+      UserLeave();
       SetLastWin32Error(ERROR_INVALID_PARAMETER);
       return -1;
    }