--- dovecot-antispam-2.0/antispam-plugin.h~	2011-11-07 10:49:47.000000000 +0100
+++ dovecot-antispam-2.0/antispam-plugin.h	2012-05-09 11:50:32.432166565 +0200
@@ -285,6 +285,31 @@
 {
 	return dict_init(uri, DICT_DATA_TYPE_STRING, username, NULL);
 }
+#elif DOVECOT_IS_EQ(2, 1)
+#define mempool_unref		pool_unref
+#define module_arg		struct module *
+#define ME(err)			MAIL_ERROR_ ##err,
+
+static inline const char *const *
+get_mail_headers(struct mail *mail, const char *hdr)
+{
+	const char *const *ret;
+	if (mail_get_headers(mail, hdr, &ret))
+		return NULL;
+	return ret;
+}
+
+static inline struct ostream *
+o_stream_create_from_fd(int fd, pool_t pool ATTR_UNUSED)
+{
+	return o_stream_create_fd(fd, 0, TRUE);
+}
+
+static inline struct dict *
+string_dict_init(const char *uri, const char *username)
+{
+	return dict_init(uri, DICT_DATA_TYPE_STRING, username, NULL);
+}
 #else
 #error "Building against this dovecot version is not supported"
 #endif