diff --git a/agen5/guile-iface.h b/agen5/guile-iface.h
index 0aeabb0..6ce3520 100644
--- a/agen5/guile-iface.h
+++ b/agen5/guile-iface.h
@@ -9,7 +9,7 @@
 # error AutoGen does not work with this version of Guile
   choke me.
 
-#elif GUILE_VERSION < 201000
+#else
 # define AG_SCM_IS_PROC(_p)           scm_is_true( scm_procedure_p(_p))
 # define AG_SCM_LIST_P(_l)            scm_is_true( scm_list_p(_l))
 # define AG_SCM_PAIR_P(_p)            scm_is_true( scm_pair_p(_p))
@@ -24,9 +24,6 @@
 # define AG_SCM_TO_ULONG(_v)          ((unsigned long)scm_to_ulong(_v))
 # define AG_SCM_VEC_P(_v)             scm_is_vector(_v)
 
-#else
-# error unknown GUILE_VERSION
-  choke me.
 #endif
 
 #endif /* MUTATING_GUILE_IFACE_H_GUARD */
diff --git a/configure b/configure
index befe20b..c4254eb 100755
--- a/configure
+++ b/configure
@@ -14191,7 +14191,7 @@ $as_echo "no" >&6; }
 		PKG_CONFIG=""
 	fi
 fi
-  _guile_versions_to_search="2.0 1.8"
+  _guile_versions_to_search="2.2 2.0 1.8"
   if test -n "$GUILE_EFFECTIVE_VERSION"; then
     _guile_tmp=""
     for v in $_guile_versions_to_search; do

diff --git a/agen5/guile-iface.h b/agen5/guile-iface.h
index 0aeabb0..6ce3520 100644
--- autogen-5.18.12/config/guile-orig.m4	2017-11-21 15:23:45.047606700 -0500
+++ autogen-5.18.12/config/guile.m4	2017-11-21 15:24:20.414686700 -0500
@@ -47,7 +47,7 @@
 # for an available version of Guile.
 #
 # By default, this macro will search for the latest stable version of
-# Guile (e.g. 2.0), falling back to the previous stable version
+# Guile (e.g. 2.2), falling back to the previous stable version
 # (e.g. 1.8) if it is available.  If no guile-@var{VERSION}.pc file is
 # found, an error is signalled.  The found version is stored in
 # @var{GUILE_EFFECTIVE_VERSION}.
@@ -61,7 +61,7 @@
 #
 AC_DEFUN([GUILE_PKG],
  [PKG_PROG_PKG_CONFIG
-  _guile_versions_to_search="m4_default([$1], [2.0 1.8])"
+  _guile_versions_to_search="m4_default([$1], [2.2 1.8])"
   if test -n "$GUILE_EFFECTIVE_VERSION"; then
     _guile_tmp=""
     for v in $_guile_versions_to_search; do
@@ -184,7 +184,7 @@
 # If @code{guile} is not found, signal an error.
 #
 # By default, this macro will search for the latest stable version of
-# Guile (e.g. 2.0). x.y or x.y.z versions can be specified. If an older
+# Guile (e.g. 2.2). x.y or x.y.z versions can be specified. If an older
 # version is found, the macro will signal an error.
 #
 # The effective version of the found @code{guile} is set to
@@ -201,7 +201,7 @@
  [AC_PATH_PROG(GUILE,guile)
   _guile_required_version="m4_default([$1], [$GUILE_EFFECTIVE_VERSION])"
   if test -z "$_guile_required_version"; then
-    _guile_required_version=2.0
+    _guile_required_version=2.2
   fi
   if test "$GUILE" = "" ; then
       AC_MSG_ERROR([guile required but not found])