diff --git a/configure.in b/configure.in
index fd6b931a827e8c5118c8423fee47cc141da1a174..852e6b70a81d5a29a2e11b56708469390c373ed9 100644
--- a/configure.in
+++ b/configure.in
@@ -4,12 +4,15 @@ dnl $Id$
 dnl Process this file with autoconf to produce a configure script.
 AC_INIT(src/lsh_types.h)
 
-AM_INIT_AUTOMAKE(lsh, 1.0.5)
+AM_INIT_AUTOMAKE(lsh, 1.0.6)
 dnl No real versioning yet, use dated snapshots instead.
 dnl AM_INIT_AUTOMAKE(lsh, esyscmd([date +snapshot-%Y-%m-%d]))
 
 AM_CONFIG_HEADER(config.h)
 
+AC_DEFINE_UNQUOTED(PREFIX, "$prefix")
+
+
 dnl This macro turns of a the Makefile.in: Makefile.am dependencies, unless
 dnl --enable-maintainer-mode is passed to ./configure. But I want
 dnl maintainermode to be *on* by default.
@@ -96,6 +99,10 @@ AC_ARG_ENABLE(srp,
   [--disable-srp    Disable the (experimental) support for SRP],,
   [enable_srp=yes])
 
+AC_ARG_ENABLE(kerberos,
+  [--disable-kerberos Don't support kerberos],,
+  [enable_kerberos=yes])
+  
 if test x$enable_srp = xyes ; then
   AC_DEFINE(WITH_SRP)
 fi
@@ -266,6 +273,10 @@ fi
 
 AC_CHECK_HEADERS(utmpx.h)
 
+if test x$enable_kerberos = xyes; then
+  AC_CHECK_HEADERS(krb5.h,, [enable_kerberos=no])
+fi
+
 dnl Some systems (in particular, Unixware) doesn't have socklen_t, but
 dnl uses size_t. Falling back to int will cause some warnings.
 
@@ -359,6 +370,26 @@ if test x$with_zlib = xyes ; then
   AC_DEFINE(WITH_ZLIB)
 fi
 
+# The kerberos libraries are needed only to support the
+# krb-check-passwd program, so we put them $KRB_LIBS, not in the
+# ordinary $LIBS.
+
+if test x$enable_kerberos = xyes; then
+  AC_CHECK_KRB_LIB(roken, strlcpy)
+  AC_CHECK_KRB_LIB(resolv, dn_expand)
+  AC_CHECK_KRB_LIB(des, des_cbc_encrypt)
+  AC_CHECK_KRB_LIB(asn1, der_get_octet_string)
+  AC_CHECK_KRB_LIB(krb5, krb5_cc_gen_new,, [enable_kerberos=no])
+fi
+
+if test x$enable_kerberos = xyes; then
+  AC_DEFINE(WITH_KERBEROS)
+  KRB_PROGRAM=lsh-krb-checkpw
+fi
+
+AC_SUBST(KRB_LIBS)
+AC_SUBST(KRB_PROGRAM)
+
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
 AC_C_INLINE