diff --git a/configure.in b/configure.in
index 3cddd0769..c25621d0f 100644
--- a/configure.in
+++ b/configure.in
@@ -55,7 +55,7 @@ AC_SUBST(LIB_krb4)
 AC_SUBST(INCLUDE_krb4)
 
 AC_ARG_ENABLE(kaserver,
-[  --enable-kaserver	   if you want the KDC to try to emulate a kaserver],
+[  --enable-kaserver	  if you want the KDC to try to emulate a kaserver],
 [
 if test "$enableval" != no; then
 	AC_DEFINE(KASERVER, 1)
@@ -66,6 +66,22 @@ if test "$enableval" != no; then
 fi
 ])
 
+otp=yes
+AC_ARG_ENABLE(otp,
+[  --disable-otp	  if you don't want OTP support],
+[
+if test "$enableval" = "no"; then
+	otp=no
+fi
+])
+if test "$otp" = "yes"; then
+	AC_DEFINE(OTP)
+	LIB_otp='-L$(top_builddir)/lib/otp -lotp'
+	OTP_dir=otp
+fi
+AC_SUBST(LIB_otp)
+AC_SUBST(OTP_dir)
+
 AC_PATH_PROG(NROFF, nroff)
 AC_PATH_PROG(GROFF, groff)
 AC_CACHE_CHECK(how to format man pages,ac_cv_sys_man_format,
@@ -227,6 +243,70 @@ dnl
 dnl Checks for prototypes and declarations
 dnl
 
+AC_PROTO_COMPAT([
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+],
+gethostbyname, struct hostent *gethostbyname(const char *))
+
+AC_PROTO_COMPAT([
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+],
+gethostbyaddr, struct hostent *gethostbyaddr(const void *, size_t, int))
+
+AC_PROTO_COMPAT([
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+],
+getservbyname, struct servent *getservbyname(const char *, const char *))
+
+AC_PROTO_COMPAT([
+#ifdef HAVE_SYSLOG_H
+#include <syslog.h>
+#endif
+],
+openlog, void openlog(const char *, int, int))
+
 AC_NEED_PROTO([
 #ifdef HAVE_CRYPT_H
 #include <crypt.h>