diff --git a/lib/active_model/serializer/adapter/base.rb b/lib/active_model/serializer/adapter/base.rb
index f27328f7..013a9705 100644
--- a/lib/active_model/serializer/adapter/base.rb
+++ b/lib/active_model/serializer/adapter/base.rb
@@ -7,9 +7,11 @@ module ActiveModel
           deprecate :inherited, 'ActiveModelSerializers::Adapter::Base.'
         end
 
+        # :nocov:
         def initialize(serializer, options = {})
           super(ActiveModelSerializers::Adapter::Base.new(serializer, options))
         end
+        # :nocov:
       end
     end
   end
diff --git a/lib/active_model/serializer/belongs_to_reflection.rb b/lib/active_model/serializer/belongs_to_reflection.rb
index 8cc5a201..a014b7a5 100644
--- a/lib/active_model/serializer/belongs_to_reflection.rb
+++ b/lib/active_model/serializer/belongs_to_reflection.rb
@@ -2,9 +2,6 @@ module ActiveModel
   class Serializer
     # @api private
     class BelongsToReflection < SingularReflection
-      def macro
-        :belongs_to
-      end
     end
   end
 end
diff --git a/lib/active_model/serializer/has_many_reflection.rb b/lib/active_model/serializer/has_many_reflection.rb
index 08be4417..60ccc481 100644
--- a/lib/active_model/serializer/has_many_reflection.rb
+++ b/lib/active_model/serializer/has_many_reflection.rb
@@ -2,9 +2,6 @@ module ActiveModel
   class Serializer
     # @api private
     class HasManyReflection < CollectionReflection
-      def macro
-        :has_many
-      end
     end
   end
 end
diff --git a/lib/active_model/serializer/has_one_reflection.rb b/lib/active_model/serializer/has_one_reflection.rb
index 5a915f7f..bf41b1d1 100644
--- a/lib/active_model/serializer/has_one_reflection.rb
+++ b/lib/active_model/serializer/has_one_reflection.rb
@@ -2,9 +2,6 @@ module ActiveModel
   class Serializer
     # @api private
     class HasOneReflection < SingularReflection
-      def macro
-        :has_one
-      end
     end
   end
 end
diff --git a/lib/active_model_serializers/adapter.rb b/lib/active_model_serializers/adapter.rb
index 93e4c044..98caab44 100644
--- a/lib/active_model_serializers/adapter.rb
+++ b/lib/active_model_serializers/adapter.rb
@@ -5,11 +5,13 @@ module ActiveModelSerializers
     private_constant :ADAPTER_MAP if defined?(private_constant)
 
     class << self # All methods are class functions
+      # :nocov:
       def new(*args)
         fail ArgumentError, 'Adapters inherit from Adapter::Base.' \
           "Adapter.new called with args: '#{args.inspect}', from" \
           "'caller[0]'."
       end
+      # :nocov:
 
       def configured_adapter
         lookup(ActiveModelSerializers.config.adapter)
diff --git a/lib/active_model_serializers/deserialization.rb b/lib/active_model_serializers/deserialization.rb
index 6b6d417b..878dd98d 100644
--- a/lib/active_model_serializers/deserialization.rb
+++ b/lib/active_model_serializers/deserialization.rb
@@ -6,8 +6,10 @@ module ActiveModelSerializers
       Adapter::JsonApi::Deserialization.parse(*args)
     end
 
+    # :nocov:
     def jsonapi_parse!(*args)
       Adapter::JsonApi::Deserialization.parse!(*args)
     end
+    # :nocov:
   end
 end
diff --git a/lib/active_model_serializers/model.rb b/lib/active_model_serializers/model.rb
index 62971392..53cd6587 100644
--- a/lib/active_model_serializers/model.rb
+++ b/lib/active_model_serializers/model.rb
@@ -38,6 +38,7 @@ module ActiveModelSerializers
     end
 
     # The following methods are needed to be minimally implemented for ActiveModel::Errors
+    # :nocov:
     def self.human_attribute_name(attr, _options = {})
       attr
     end
@@ -45,5 +46,6 @@ module ActiveModelSerializers
     def self.lookup_ancestors
       [self]
     end
+    # :nocov:
   end
 end
diff --git a/lib/active_model_serializers/railtie.rb b/lib/active_model_serializers/railtie.rb
index 971393fe..c7d6c0d1 100644
--- a/lib/active_model_serializers/railtie.rb
+++ b/lib/active_model_serializers/railtie.rb
@@ -32,11 +32,13 @@ module ActiveModelSerializers
       end
     end
 
+    # :nocov:
     generators do |app|
       Rails::Generators.configure!(app.config.generators)
       Rails::Generators.hidden_namespaces.uniq!
       require 'generators/rails/resource_override'
     end
+    # :nocov:
 
     if Rails.env.test?
       ActionController::TestCase.send(:include, ActiveModelSerializers::Test::Schema)