diff --git a/test/prism/ractor_test.rb b/test/prism/ractor_test.rb
index 68fc0508c8..c090ecc32b 100644
--- a/test/prism/ractor_test.rb
+++ b/test/prism/ractor_test.rb
@@ -69,6 +69,7 @@ module Prism
 
       writer.close
       result = reader.gets.chomp
+      reader.close
 
       Process.wait(pid)
       result