diff --git a/Library/Homebrew/extend/ENV/shared.rb b/Library/Homebrew/extend/ENV/shared.rb
index 9e423ffdc3..01a7caafdb 100644
--- a/Library/Homebrew/extend/ENV/shared.rb
+++ b/Library/Homebrew/extend/ENV/shared.rb
@@ -1,3 +1,5 @@
+require 'formula'
+
 module SharedEnvExtension
   CC_FLAG_VARS = %w{CFLAGS CXXFLAGS OBJCFLAGS OBJCXXFLAGS}
   FC_FLAG_VARS = %w{FCFLAGS FFLAGS}