diff --git a/reactos/subsystems/win32/win32k/objects/dc.c b/reactos/subsystems/win32/win32k/objects/dc.c
index f33134f1f69..dec5ee7fff2 100644
--- a/reactos/subsystems/win32/win32k/objects/dc.c
+++ b/reactos/subsystems/win32/win32k/objects/dc.c
@@ -1888,7 +1888,7 @@ NtGdiExtGetObjectW(IN HANDLE hGdiObj,
         _SEH_TRY
         {
             // Probe the buffer and copy it
-            ProbeForWrite(lpBuffer, cbCopyCount, 1);
+            ProbeForWrite(lpBuffer, cbCopyCount, sizeof(WORD));
             RtlCopyMemory(lpBuffer, &Object, cbCopyCount);
         }
         _SEH_HANDLE