--- src/enigma.hh.orig	2003-09-11 21:35:23.817316216 -0400
+++ src/enigma.hh	2003-09-11 21:32:33.295239512 -0400
@@ -29,6 +29,7 @@
 #include "px/math.hh"
 #include "px/tools.hh"
 
+#include <assert.h>
 #include <string>
 #include <vector>
 #include <iosfwd>