-STEPMAKE_GUILE_DEVEL(REQUIRED, 1.6.7)
-STEPMAKE_MAKEINFO(REQUIRED, 4.8)
+STEPMAKE_GUILE_DEVEL(REQUIRED, 1.8.2)
+
+# check for 2 typedefs added in Guile 1.9
+save_CXXFLAGS="$CXXFLAGS"
+CXXFLAGS="$GUILE_CFLAGS $CXXFLAGS"
+AC_CHECK_TYPES([scm_t_hash_fold_fn, scm_t_hash_handle_fn],
+ [AC_DEFINE(HAVE_GUILE_HASH_FUNC)], [],
+ [#include <libguile.h>])
+CXXFLAGS="$save_CXXFLAGS"
+
+## check rational bugfix.
+save_CPPFLAGS="$CPPFLAGS"
+CPPFLAGS="$GUILE_CFLAGS $CPPFLAGS"
+AC_MSG_CHECKING(GUILE rational bugfix)
+AC_PREPROC_IFELSE([AC_LANG_SOURCE([[#include <libguile.h>
+#ifdef SCM_FRACTION_REDUCED_BIT
+#error
+#endif
+]])],[AC_MSG_RESULT(ok)],[REQUIRED="$REQUIRED GUILE-with-rational-bugfix"
+AC_MSG_RESULT(Must have patched GUILE rational support. See INSTALL.txt)])
+CPPFLAGS="$save_CPPFLAGS"
+
+