diff --git a/lgi/class.lua b/lgi/class.lua
index 84f91eb..b03e253 100644
--- a/lgi/class.lua
+++ b/lgi/class.lua
@@ -20,7 +20,7 @@ local component = require 'lgi.component'
 local record = require 'lgi.record'
 local ffi = require 'lgi.ffi'
 local ti = ffi.types
-local GObject = gi.require 'GObject'
+local GObject = assert(gi.require('GObject'))
 
 -- Implementation of class and interface component loading.
 local class = {
diff --git a/lgi/ffi.lua b/lgi/ffi.lua
index fc66ac5..1042632 100644
--- a/lgi/ffi.lua
+++ b/lgi/ffi.lua
@@ -21,8 +21,8 @@ local record = require 'lgi.record'
 
 local ffi = {}
 
-local gobject = gi.require('GObject')
-local glib = gi.require('GLib')
+local gobject = assert(gi.require('GObject'))
+local glib = assert(gi.require('GLib'))
 
 -- Gather all basic types.  We have to 'steal' them from well-known
 -- declarations, because girepository API does not allow synthesizing