--- libmng_conf.h	2006-10-03 05:11:10.000000000 -0400
+++ libmng_conf.h.new	2006-10-03 05:11:03.000000000 -0400
@@ -94,6 +94,10 @@
    so choose the one you've defined in jconfig.h; if you don't know what
    the heck I'm talking about, just leave it at 8-bit support (thank you!) */
 
+#ifndef HAVE_LIBJPEG
+#define MNG_NO_INCLUDE_JNG
+#endif
+
 #ifndef MNG_NO_INCLUDE_JNG
 #ifdef MNG_SUPPORT_FULL                /* full support includes JNG */
 #define MNG_SUPPORT_IJG6B