diff --git a/RTjpegN.c b/RTjpegN.c
index c6a704d64e..db8cd8106c 100644
--- a/RTjpegN.c
+++ b/RTjpegN.c
@@ -25,6 +25,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+
+#include "config.h"
+#ifdef HAVE_MMX
+#define MMX
+#endif
+
 #include "RTjpegN.h"
 
 #ifdef MMX