diff -up abook-0.6.0pre2/configure.in.ac269 abook-0.6.0pre2/configure.in
--- abook-0.6.0pre2/configure.in.ac269	2006-09-05 09:55:35.000000000 +0200
+++ abook-0.6.0pre2/configure.in	2014-02-27 12:33:06.611880272 +0100
@@ -42,10 +42,6 @@ dnl ----------------------
 
 AC_PROG_CC
 AC_ISC_POSIX
-AM_C_PROTOTYPES
-if test "x$U" != "x"; then
-	AC_MSG_ERROR(Compiler not ANSI compliant)
-fi
 AC_C_INLINE
 AC_PROG_INSTALL
 AC_HEADER_STDC