diff --git a/lib/spring/application.rb b/lib/spring/application.rb
index b6054abf..8c658e5a 100644
--- a/lib/spring/application.rb
+++ b/lib/spring/application.rb
@@ -1,5 +1,4 @@
 require "spring/boot"
-require "set"
 require "pty"
 
 module Spring
diff --git a/lib/spring/client/binstub.rb b/lib/spring/client/binstub.rb
index 98b42786..1e2feac3 100644
--- a/lib/spring/client/binstub.rb
+++ b/lib/spring/client/binstub.rb
@@ -1,5 +1,3 @@
-require 'set'
-
 module Spring
   module Client
     class Binstub < Command
diff --git a/lib/spring/client/rails.rb b/lib/spring/client/rails.rb
index a241e0ea..23029f29 100644
--- a/lib/spring/client/rails.rb
+++ b/lib/spring/client/rails.rb
@@ -1,5 +1,3 @@
-require "set"
-
 module Spring
   module Client
     class Rails < Command
diff --git a/lib/spring/watcher/abstract.rb b/lib/spring/watcher/abstract.rb
index 27275984..108510e2 100644
--- a/lib/spring/watcher/abstract.rb
+++ b/lib/spring/watcher/abstract.rb
@@ -1,4 +1,3 @@
-require "set"
 require "pathname"
 require "mutex_m"