Index: unnethack-3.5.3/include/unixconf.h
===================================================================
--- unnethack-3.5.3.orig/include/unixconf.h	2010-09-09 10:53:23.383127730 +0400
+++ unnethack-3.5.3/include/unixconf.h	2010-09-09 10:54:04.351131167 +0400
@@ -279,7 +279,9 @@
 #endif
 #define tgetch getchar
 
-#define SHELL		/* do not delete the '!' command */
+#ifdef SHELL
+#undef SHELL		/* do not delete the '!' command */
+#endif
 
 #if defined(POSIX_TYPES) || defined(__GNUC__)
 #include <stdlib.h>
