6 files changed, 6 insertions, 0 deletions
diff --git a/lib/rubygems/source/git.rb b/lib/rubygems/source/git.rb
index 35c2270a74..7096ebe617 100644
--- a/lib/rubygems/source/git.rb
+++ b/lib/rubygems/source/git.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'digest'
 require 'rubygems/util'
 
diff --git a/lib/rubygems/source/installed.rb b/lib/rubygems/source/installed.rb
index bd05c75af1..3327010768 100644
--- a/lib/rubygems/source/installed.rb
+++ b/lib/rubygems/source/installed.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 ##
 # Represents an installed gem.  This is used for dependency resolution.
 
diff --git a/lib/rubygems/source/local.rb b/lib/rubygems/source/local.rb
index 8057921163..a320ff1c66 100644
--- a/lib/rubygems/source/local.rb
+++ b/lib/rubygems/source/local.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 ##
 # The local source finds gems in the current directory for fulfilling
 # dependencies.
diff --git a/lib/rubygems/source/lock.rb b/lib/rubygems/source/lock.rb
index 2ba7702bda..98fef5a4d1 100644
--- a/lib/rubygems/source/lock.rb
+++ b/lib/rubygems/source/lock.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 ##
 # A Lock source wraps an installed gem's source and sorts before other sources
 # during dependency resolution.  This allows RubyGems to prefer gems from
diff --git a/lib/rubygems/source/specific_file.rb b/lib/rubygems/source/specific_file.rb
index 250a839203..790e424033 100644
--- a/lib/rubygems/source/specific_file.rb
+++ b/lib/rubygems/source/specific_file.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 ##
 # A source representing a single .gem file.  This is used for installation of
 # local gems.
diff --git a/lib/rubygems/source/vendor.rb b/lib/rubygems/source/vendor.rb
index 2d936231c1..057d54ebea 100644
--- a/lib/rubygems/source/vendor.rb
+++ b/lib/rubygems/source/vendor.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 ##
 # This represents a vendored source that is similar to an installed gem.