diff --git a/reactos/base/system/smss/print.c b/reactos/base/system/smss/print.c
index 9b27cf5cfcb..e8285a50554 100644
--- a/reactos/base/system/smss/print.c
+++ b/reactos/base/system/smss/print.c
@@ -25,6 +25,8 @@
  */
 #include "smss.h"
 
+#define NDEBUG
+#include <debug.h>
 
 VOID STDCALL DisplayString(LPCWSTR lpwString)
 {