9 files changed, 9 insertions, 0 deletions
diff --git a/ext/digest/bubblebabble/extconf.rb b/ext/digest/bubblebabble/extconf.rb
index 1214add293..21feed57fb 100644
--- a/ext/digest/bubblebabble/extconf.rb
+++ b/ext/digest/bubblebabble/extconf.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'mkmf'
 
 $defs << "-DHAVE_CONFIG_H"
diff --git a/ext/digest/digest_conf.rb b/ext/digest/digest_conf.rb
index 6a4ef6f176..432652852f 100644
--- a/ext/digest/digest_conf.rb
+++ b/ext/digest/digest_conf.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 def digest_conf(name, hdr = name, funcs = nil, types = nil)
   unless with_config("bundled-#{name}")
     cc = with_config("common-digest")
diff --git a/ext/digest/extconf.rb b/ext/digest/extconf.rb
index a20ca8d68f..a8c68850a2 100644
--- a/ext/digest/extconf.rb
+++ b/ext/digest/extconf.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 # $RoughId: extconf.rb,v 1.6 2001/07/13 15:38:27 knu Exp $
 # $Id$
 
diff --git a/ext/digest/lib/digest.rb b/ext/digest/lib/digest.rb
index ef43c46ac3..d6daf36f80 100644
--- a/ext/digest/lib/digest.rb
+++ b/ext/digest/lib/digest.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 require 'digest.so'
 
 module Digest
diff --git a/ext/digest/md5/extconf.rb b/ext/digest/md5/extconf.rb
index 05a990cdd2..dead9a228b 100644
--- a/ext/digest/md5/extconf.rb
+++ b/ext/digest/md5/extconf.rb
@@ -1,4 +1,5 @@
 # -*- coding: us-ascii -*-
+# frozen_string_literal: false
 # $RoughId: extconf.rb,v 1.3 2001/08/14 19:54:51 knu Exp $
 # $Id$
 
diff --git a/ext/digest/rmd160/extconf.rb b/ext/digest/rmd160/extconf.rb
index 15fd095cf2..a02ba56169 100644
--- a/ext/digest/rmd160/extconf.rb
+++ b/ext/digest/rmd160/extconf.rb
@@ -1,4 +1,5 @@
 # -*- coding: us-ascii -*-
+# frozen_string_literal: false
 # $RoughId: extconf.rb,v 1.3 2001/08/14 19:54:51 knu Exp $
 # $Id$
 
diff --git a/ext/digest/sha1/extconf.rb b/ext/digest/sha1/extconf.rb
index 03cbf66b5e..0ff4158bef 100644
--- a/ext/digest/sha1/extconf.rb
+++ b/ext/digest/sha1/extconf.rb
@@ -1,4 +1,5 @@
 # -*- coding: us-ascii -*-
+# frozen_string_literal: false
 # $RoughId: extconf.rb,v 1.3 2001/08/14 19:54:51 knu Exp $
 # $Id$
 
diff --git a/ext/digest/sha2/extconf.rb b/ext/digest/sha2/extconf.rb
index fe515457b7..5c7f76c7f3 100644
--- a/ext/digest/sha2/extconf.rb
+++ b/ext/digest/sha2/extconf.rb
@@ -1,4 +1,5 @@
 # -*- coding: us-ascii -*-
+# frozen_string_literal: false
 # $RoughId: extconf.rb,v 1.4 2001/08/14 19:54:51 knu Exp $
 # $Id$
 
diff --git a/ext/digest/sha2/lib/sha2.rb b/ext/digest/sha2/lib/sha2.rb
index 58d12e9b09..58ff9f5cf0 100644
--- a/ext/digest/sha2/lib/sha2.rb
+++ b/ext/digest/sha2/lib/sha2.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: false
 #--
 # sha2.rb - defines Digest::SHA2 class which wraps up the SHA256,
 #           SHA384, and SHA512 classes.