diff --git a/sys/dev/dpt/dpt.h b/sys/dev/dpt/dpt.h
index c31e6e38e302..eaf1ac63a95d 100644
--- a/sys/dev/dpt/dpt.h
+++ b/sys/dev/dpt/dpt.h
@@ -142,7 +142,7 @@ typedef void *physaddr;
  */
 #define DPT_NO_CACHE		       	0
 #define DPT_CACHE_WRITETHROUGH		1
-#define DPT_CACHE_WRITEBACK			-2
+#define DPT_CACHE_WRITEBACK		2
 
 #define min(a,b) ((a<b)?(a):(b))