--- a/configure.ac
+++ b/configure.ac
@@ -34,8 +34,12 @@
 AC_MSG_CHECKING([whether to enable debugging])
 AC_ARG_ENABLE([debug],
   [AS_HELP_STRING([--enable-debug],[build with extra debugging messages])],
+  if test x$enableval = xyes; then
   [AC_MSG_RESULT([yes])
-   AC_DEFINE([DEBUG], 1, [Define this to enable debugging messages])],
+   AC_DEFINE([DEBUG], 1, [Define this to enable debugging messages])]
+  else
+  [AC_MSG_RESULT([no])]
+  fi,
   [AC_MSG_RESULT([no])])
 
 AC_ARG_WITH([electric-fence],