diff --git a/esp.c b/esp.c
index e8bfbd03..619df437 100644
--- a/esp.c
+++ b/esp.c
@@ -106,3 +106,27 @@ int verify_packet_seqno(struct openconnect_info *vpninfo,
 		return 0;
 	}
 }
+
+
+int esp_setup(struct openconnect_info *vpninfo, int dtls_attempt_period)
+{
+	if (vpninfo->dtls_state == DTLS_DISABLED)
+		return -EINVAL;
+
+	vpn_progress(vpninfo, PRG_ERR,
+		     _("ESP not implemented yet\n"));
+	return -EINVAL;
+}
+
+int esp_mainloop(struct openconnect_info *vpninfo, int *timeout)
+{
+	return 0;
+}
+
+void esp_close(struct openconnect_info *vpninfo)
+{
+}
+
+void esp_shutdown(struct openconnect_info *vpninfo)
+{
+}
diff --git a/library.c b/library.c
index 34695ba6..d74ba035 100644
--- a/library.c
+++ b/library.c
@@ -120,11 +120,10 @@ void openconnect_set_juniper(struct openconnect_info *vpninfo)
 	vpninfo->proto.tcp_mainloop = oncp_mainloop;
 	vpninfo->proto.add_http_headers = oncp_common_headers;
 	vpninfo->proto.obtain_cookie = oncp_obtain_cookie;
-	vpninfo->proto.udp_setup = NULL;
-	vpninfo->proto.udp_mainloop = NULL;
-	vpninfo->proto.udp_close = NULL;
-	vpninfo->proto.udp_shutdown = NULL;
-	vpninfo->dtls_state = DTLS_DISABLED;
+	vpninfo->proto.udp_setup = esp_setup;
+	vpninfo->proto.udp_mainloop = esp_mainloop;
+	vpninfo->proto.udp_close = esp_close;
+	vpninfo->proto.udp_shutdown = esp_shutdown;
 }
 
 int openconnect_setup_dtls(struct openconnect_info *vpninfo,
diff --git a/openconnect-internal.h b/openconnect-internal.h
index b351f6a1..db5db797 100644
--- a/openconnect-internal.h
+++ b/openconnect-internal.h
@@ -765,6 +765,10 @@ int load_pkcs11_certificate(struct openconnect_info *vpninfo);
 /* esp.c */
 int verify_packet_seqno(struct openconnect_info *vpninfo,
 			struct esp *esp, uint32_t seq);
+int esp_setup(struct openconnect_info *vpninfo, int dtls_attempt_period);
+int esp_mainloop(struct openconnect_info *vpninfo, int *timeout);
+void esp_close(struct openconnect_info *vpninfo);
+void esp_shutdown(struct openconnect_info *vpninfo);
 
 /* gnutls-esp.c */
 int setup_esp_keys(struct openconnect_info *vpninfo);