diff --git a/Library/Homebrew/download_strategy.rb b/Library/Homebrew/download_strategy.rb
index 19ce95b48a1d810030fe06aa561d1da084c54ff4..d63b2e681e0aecd1c440c13c060973a7e99cc30d 100644
--- a/Library/Homebrew/download_strategy.rb
+++ b/Library/Homebrew/download_strategy.rb
@@ -1,5 +1,6 @@
 require "utils/json"
 require "rexml/document"
+require "time"
 
 class AbstractDownloadStrategy
   include FileUtils