diff --git a/lib/vips.rb b/lib/vips.rb
index 45c103d..3d55024 100644
--- a/lib/vips.rb
+++ b/lib/vips.rb
@@ -48,7 +48,7 @@ module Vips
   begin
     attach_function :g_malloc, [:size_t], :pointer
     @@is_unified = true
-  rescue => e
+  rescue FFI::NotFoundError
     @@is_unified = false
   end