diff --git a/allocations_test.rb b/allocations_test.rb
index d3f0e62..880d911 100755
--- a/allocations_test.rb
+++ b/allocations_test.rb
@@ -4,6 +4,8 @@
 # NOTE: This is not a quickdraw test becuase it needs to be run in a single thread.
 
 require "literal"
+require "set"
+
 include Literal::Types
 
 def count_allocations