diff --git a/activemodel/Rakefile b/activemodel/Rakefile
index d94f857614..d62c7b46c8 100644
--- a/activemodel/Rakefile
+++ b/activemodel/Rakefile
@@ -2,7 +2,7 @@ require "rake/testtask"
 
 dir = File.dirname(__FILE__)
 
-task :default => :test
+task default: :test
 
 task :package
 
diff --git a/activemodel/test/cases/attribute_methods_test.rb b/activemodel/test/cases/attribute_methods_test.rb
index 89166f2f1e..676459cc8e 100644
--- a/activemodel/test/cases/attribute_methods_test.rb
+++ b/activemodel/test/cases/attribute_methods_test.rb
@@ -48,7 +48,7 @@ class ModelWithAttributesWithSpaces
   include ActiveModel::AttributeMethods
 
   def attributes
-    { :'foo bar' => "value of foo bar"}
+    { 'foo bar': "value of foo bar"}
   end
 
 private
@@ -67,7 +67,7 @@ class << self
   end
 
   def attributes
-    { :'a?b' => "value of a?b" }
+    { 'a?b': "value of a?b" }
   end
 
 private
diff --git a/activemodel/test/cases/translation_test.rb b/activemodel/test/cases/translation_test.rb
index 95655e03b4..69a3acd957 100644
--- a/activemodel/test/cases/translation_test.rb
+++ b/activemodel/test/cases/translation_test.rb
@@ -56,7 +56,7 @@ def test_translated_model_attributes_with_ancestors_fallback
   def test_translated_model_attributes_with_attribute_matching_namespaced_model_name
     I18n.backend.store_translations "en", activemodel: { attributes: {
       person: { gender: "person gender"},
-      :"person/gender" => { attribute: "person gender attribute" }
+      "person/gender": { attribute: "person gender attribute" }
     } }
 
     assert_equal "person gender", Person.human_attribute_name("gender")
@@ -64,12 +64,12 @@ def test_translated_model_attributes_with_attribute_matching_namespaced_model_na
   end
 
   def test_translated_deeply_nested_model_attributes
-    I18n.backend.store_translations "en", activemodel: { attributes: { :"person/contacts/addresses" => { street: "Deeply Nested Address Street" } } }
+    I18n.backend.store_translations "en", activemodel: { attributes: { "person/contacts/addresses": { street: "Deeply Nested Address Street" } } }
     assert_equal "Deeply Nested Address Street", Person.human_attribute_name("contacts.addresses.street")
   end
 
   def test_translated_nested_model_attributes
-    I18n.backend.store_translations "en", activemodel: { attributes: { :"person/addresses" => { street: "Person Address Street" } } }
+    I18n.backend.store_translations "en", activemodel: { attributes: { "person/addresses": { street: "Person Address Street" } } }
     assert_equal "Person Address Street", Person.human_attribute_name("addresses.street")
   end
 
diff --git a/activemodel/test/cases/validations/validates_test.rb b/activemodel/test/cases/validations/validates_test.rb
index af89a5e0b8..011033606e 100644
--- a/activemodel/test/cases/validations/validates_test.rb
+++ b/activemodel/test/cases/validations/validates_test.rb
@@ -53,7 +53,7 @@ def test_validates_with_validator_class
   end
 
   def test_validates_with_namespaced_validator_class
-    Person.validates :karma, :'namespace/email' => true
+    Person.validates :karma, 'namespace/email': true
     person = Person.new
     person.valid?
     assert_equal ["is not an email"], person.errors[:karma]