diff --git a/spec/filelock_spec.rb b/spec/filelock_spec.rb
index 6c99328..080d5c8 100644
--- a/spec/filelock_spec.rb
+++ b/spec/filelock_spec.rb
@@ -1,4 +1,5 @@
 require 'filelock'
+require 'pathname'
 require 'tempfile'
 require 'timeout'