diff --git a/libnm/NetworkManager.h b/libnm/NetworkManager.h
index 35cd07aeca..b5dab8fd84 100644
--- a/libnm/NetworkManager.h
+++ b/libnm/NetworkManager.h
@@ -88,6 +88,7 @@
 #include <nm-vpn-editor.h>
 #include <nm-vpn-editor-plugin.h>
 #include <nm-vpn-plugin-info.h>
+#include <nm-vpn-service-plugin.h>
 #include <nm-wimax-nsp.h>
 
 #undef __NETWORKMANAGER_H_INSIDE__
diff --git a/libnm/nm-vpn-service-plugin.h b/libnm/nm-vpn-service-plugin.h
index f8b4ff8761..29319189f9 100644
--- a/libnm/nm-vpn-service-plugin.h
+++ b/libnm/nm-vpn-service-plugin.h
@@ -22,6 +22,10 @@
 #ifndef __NM_VPN_SERVICE_PLUGIN_H__
 #define __NM_VPN_SERVICE_PLUGIN_H__
 
+#if !defined (__NETWORKMANAGER_H_INSIDE__) && !defined (NETWORKMANAGER_COMPILATION)
+#error "Only <NetworkManager.h> can be included directly."
+#endif
+
 #include <gio/gio.h>
 #include <nm-vpn-dbus-interface.h>
 #include <nm-connection.h>