diff --git a/desktop/knockout.c b/desktop/knockout.c
index 8f800cedf..16029c3d7 100644
--- a/desktop/knockout.c
+++ b/desktop/knockout.c
@@ -9,6 +9,8 @@
  * Knockout rendering (implementation).
  */
 
+#define NDEBUG
+
 #include <assert.h>
 #include <string.h>
 #include "netsurf/desktop/knockout.h"
@@ -16,8 +18,6 @@
 #include "netsurf/image/bitmap.h"
 #include "netsurf/utils/log.h"
 
-#define NDEBUG
-
 #define KNOCKOUT_ENTRIES 3072	/* 40 bytes each */
 #define KNOCKOUT_BOXES 768	/* 28 bytes each */
 #define KNOCKOUT_POLYGONS 3072	/* 4 bytes each */