diff --git a/subsystems/ntvdm/bios.c b/subsystems/ntvdm/bios.c
index 1f82d88fb47..4c45004b107 100644
--- a/subsystems/ntvdm/bios.c
+++ b/subsystems/ntvdm/bios.c
@@ -91,7 +91,7 @@ static COORD BiosVideoAddressToCoord(ULONG Address)
 
     if (!GetConsoleScreenBufferInfo(ConsoleOutput, &ConsoleInfo))
     {
-        assert(0);
+        ASSERT(FALSE);
         return Result;
     }
 
diff --git a/subsystems/ntvdm/ntvdm.c b/subsystems/ntvdm/ntvdm.c
index 93448910383..957a9aa4b67 100644
--- a/subsystems/ntvdm/ntvdm.c
+++ b/subsystems/ntvdm/ntvdm.c
@@ -8,8 +8,6 @@
 
 #include "ntvdm.h"
 
-#define NDEBUG
-
 BOOLEAN VdmRunning = TRUE;
 LPVOID BaseAddress = NULL;
 LPCWSTR ExceptionName[] =
diff --git a/subsystems/ntvdm/ntvdm.h b/subsystems/ntvdm/ntvdm.h
index 04b4ecc6467..ddc4ac5bee5 100644
--- a/subsystems/ntvdm/ntvdm.h
+++ b/subsystems/ntvdm/ntvdm.h
@@ -12,8 +12,9 @@
 #include <tchar.h>
 #include <stdio.h>
 #include <conio.h>
-#include <assert.h>
 #include <stdarg.h>
+
+#define NDEBUG
 #include <debug.h>
 
 /* DEFINES ********************************************************************/