6 files changed, 22 insertions, 4 deletions
diff --git a/lib/did_you_mean/core_ext/name_error.rb b/lib/did_you_mean/core_ext/name_error.rb
index 7e99282b41..eb3ef117a0 100644
--- a/lib/did_you_mean/core_ext/name_error.rb
+++ b/lib/did_you_mean/core_ext/name_error.rb
@@ -26,7 +26,7 @@ module DidYouMean
     end
 
     def spell_checker
-      SPELL_CHECKERS[self.class.to_s].new(self)
+      DidYouMean.spell_checkers[self.class.to_s].new(self)
     end
   end
 end
diff --git a/lib/did_you_mean/formatter.rb b/lib/did_you_mean/formatter.rb
index 01eb59100a..c43748f707 100644
--- a/lib/did_you_mean/formatter.rb
+++ b/lib/did_you_mean/formatter.rb
@@ -26,10 +26,19 @@ module DidYouMean
     #
     #   # => nil
     #
-    def message_for(corrections)
+    def self.message_for(corrections)
       corrections.empty? ? "" : "\nDid you mean?  #{corrections.join("\n               ")}"
     end
+
+    def message_for(corrections)
+      warn "The instance method #message_for has been deprecated. Please use the class method " \
+           "DidYouMean::Formatter.message_for(...) instead."
+
+      self.class.message_for(corrections)
+    end
   end
 
   PlainFormatter = Formatter
+
+  deprecate_constant :PlainFormatter
 end
diff --git a/lib/did_you_mean/spell_checkers/method_name_checker.rb b/lib/did_you_mean/spell_checkers/method_name_checker.rb
index 0483127d6f..d8ebaa4616 100644
--- a/lib/did_you_mean/spell_checkers/method_name_checker.rb
+++ b/lib/did_you_mean/spell_checkers/method_name_checker.rb
@@ -6,6 +6,7 @@ module DidYouMean
 
     NAMES_TO_EXCLUDE = { NilClass => nil.methods }
     NAMES_TO_EXCLUDE.default = []
+    Ractor.make_shareable(NAMES_TO_EXCLUDE) if defined?(Ractor)
 
     # +MethodNameChecker::RB_RESERVED_WORDS+ is the list of reserved words in
     # Ruby that take an argument. Unlike
@@ -36,6 +37,8 @@ module DidYouMean
       yield
     )
 
+    Ractor.make_shareable(RB_RESERVED_WORDS) if defined?(Ractor)
+
     def initialize(exception)
       @method_name  = exception.name
       @receiver     = exception.receiver
diff --git a/lib/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb b/lib/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb
index 3e51b4fa3a..36d00349c6 100644
--- a/lib/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb
+++ b/lib/did_you_mean/spell_checkers/name_error_checkers/variable_name_checker.rb
@@ -8,6 +8,7 @@ module DidYouMean
 
     NAMES_TO_EXCLUDE = { 'foo' => [:fork, :for] }
     NAMES_TO_EXCLUDE.default = []
+    Ractor.make_shareable(NAMES_TO_EXCLUDE) if defined?(Ractor)
 
     # +VariableNameChecker::RB_RESERVED_WORDS+ is the list of all reserved
     # words in Ruby. They could be declared like methods are, and a typo would
@@ -62,6 +63,8 @@ module DidYouMean
       __ENCODING__
     )
 
+    Ractor.make_shareable(RB_RESERVED_WORDS) if defined?(Ractor)
+
     def initialize(exception)
       @name       = exception.name.to_s.tr("@", "")
       @lvar_names = exception.respond_to?(:local_variables) ? exception.local_variables : []
diff --git a/lib/did_you_mean/spell_checkers/require_path_checker.rb b/lib/did_you_mean/spell_checkers/require_path_checker.rb
index e4cdb9f43d..586ced37de 100644
--- a/lib/did_you_mean/spell_checkers/require_path_checker.rb
+++ b/lib/did_you_mean/spell_checkers/require_path_checker.rb
@@ -9,7 +9,10 @@ module DidYouMean
     attr_reader :path
 
     INITIAL_LOAD_PATH = $LOAD_PATH.dup.freeze
-    ENV_SPECIFIC_EXT  = ".#{RbConfig::CONFIG["DLEXT"]}"
+    Ractor.make_shareable(INITIAL_LOAD_PATH) if defined?(Ractor)
+
+    ENV_SPECIFIC_EXT = ".#{RbConfig::CONFIG["DLEXT"]}"
+    Ractor.make_shareable(ENV_SPECIFIC_EXT) if defined?(Ractor)
 
     private_constant :INITIAL_LOAD_PATH, :ENV_SPECIFIC_EXT
 
diff --git a/lib/did_you_mean/version.rb b/lib/did_you_mean/version.rb
index 8df73e1d62..b5fe50b5ed 100644
--- a/lib/did_you_mean/version.rb
+++ b/lib/did_you_mean/version.rb
@@ -1,3 +1,3 @@
 module DidYouMean
-  VERSION = "1.6.0-alpha"
+  VERSION = "1.6.1".freeze
 end