3 files changed, 15 insertions, 6 deletions
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index d7e682d406..3a692a3e64 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -63,9 +63,9 @@ module ActiveModel
     MESSAGE_OPTIONS = [:message]
 
     class << self
-      attr_accessor :i18n_full_message # :nodoc:
+      attr_accessor :i18n_customize_full_message # :nodoc:
     end
-    self.i18n_full_message = false
+    self.i18n_customize_full_message = false
 
     attr_reader :messages, :details
 
@@ -413,7 +413,7 @@ module ActiveModel
       return message if attribute == :base
       attribute = attribute.to_s
 
-      if self.class.i18n_full_message && @base.class.respond_to?(:i18n_scope)
+      if self.class.i18n_customize_full_message && @base.class.respond_to?(:i18n_scope)
         attribute = attribute.remove(/\[\d\]/)
         parts = attribute.split(".")
         attribute_name = parts.pop
diff --git a/activemodel/lib/active_model/railtie.rb b/activemodel/lib/active_model/railtie.rb
index 0ed70bd473..eb7901c7e9 100644
--- a/activemodel/lib/active_model/railtie.rb
+++ b/activemodel/lib/active_model/railtie.rb
@@ -13,8 +13,8 @@ module ActiveModel
       ActiveModel::SecurePassword.min_cost = Rails.env.test?
     end
 
-    initializer "active_model.i18n_full_message" do
-      ActiveModel::Errors.i18n_full_message = config.active_model.delete(:i18n_full_message) || false
+    initializer "active_model.i18n_customize_full_message" do
+      ActiveModel::Errors.i18n_customize_full_message = config.active_model.delete(:i18n_customize_full_message) || false
     end
   end
 end
diff --git a/activemodel/lib/active_model/type/boolean.rb b/activemodel/lib/active_model/type/boolean.rb
index f6c6efbc87..e64d2c793c 100644
--- a/activemodel/lib/active_model/type/boolean.rb
+++ b/activemodel/lib/active_model/type/boolean.rb
@@ -14,7 +14,16 @@ module ActiveModel
     # - Empty strings are coerced to +nil+
     # - All other values will be coerced to +true+
     class Boolean < Value
-      FALSE_VALUES = [false, 0, "0", "f", "F", "false", "FALSE", "off", "OFF"].to_set
+      FALSE_VALUES = [
+        false, 0,
+        "0", :"0",
+        "f", :f,
+        "F", :F,
+        "false", :false,
+        "FALSE", :FALSE,
+        "off", :off,
+        "OFF", :OFF,
+      ].to_set.freeze
 
       def type # :nodoc:
         :boolean