diff --git a/lib/factory_bot/definition.rb b/lib/factory_bot/definition.rb
index 4aded74..ab6b341 100644
--- a/lib/factory_bot/definition.rb
+++ b/lib/factory_bot/definition.rb
@@ -30,7 +30,7 @@ module FactoryBot
     end
 
     def to_create(&block)
-      if block_given?
+      if block
         @to_create = block
       else
         aggregate_from_traits_and_self(:to_create) { @to_create }.last
diff --git a/lib/factory_bot/registry.rb b/lib/factory_bot/registry.rb
index ca55787..c7eb039 100644
--- a/lib/factory_bot/registry.rb
+++ b/lib/factory_bot/registry.rb
@@ -25,7 +25,7 @@ module FactoryBot
       raise key_error_with_custom_message(e)
     end
 
-    alias [] find
+    alias_method :[], :find
 
     def register(name, item)
       @items[name] = item
diff --git a/lib/factory_bot/syntax/default.rb b/lib/factory_bot/syntax/default.rb
index 0ef7608..fd391d0 100644
--- a/lib/factory_bot/syntax/default.rb
+++ b/lib/factory_bot/syntax/default.rb
@@ -15,7 +15,7 @@ module FactoryBot
         def factory(name, options = {}, &block)
           factory = Factory.new(name, options)
           proxy = FactoryBot::DefinitionProxy.new(factory.definition)
-          proxy.instance_eval(&block) if block_given?
+          proxy.instance_eval(&block) if block
 
           Internal.register_factory(factory)
 
diff --git a/lib/factory_bot/trait.rb b/lib/factory_bot/trait.rb
index 944eee7..710783b 100644
--- a/lib/factory_bot/trait.rb
+++ b/lib/factory_bot/trait.rb
@@ -9,7 +9,7 @@ module FactoryBot
       @definition = Definition.new(@name)
       proxy = FactoryBot::DefinitionProxy.new(@definition)
 
-      if block_given?
+      if block
         proxy.instance_eval(&@block)
       end
     end
diff --git a/spec/factory_bot/attribute/association_spec.rb b/spec/factory_bot/attribute/association_spec.rb
index 4d54871..b9bcfac 100644
--- a/spec/factory_bot/attribute/association_spec.rb
+++ b/spec/factory_bot/attribute/association_spec.rb
@@ -6,15 +6,14 @@ describe FactoryBot::Attribute::Association do
 
   subject { FactoryBot::Attribute::Association.new(name, factory, overrides) }
 
-  module MissingMethods
-    def association(*args)
-    end
-  end
-
   before do
     # Define an '#association' instance method allowing it to be mocked.
     # Ususually this is determined via '#method_missing'
-    subject.extend(MissingMethods)
+    missing_methods = Module.new {
+      def association(*args)
+      end
+    }
+    subject.extend(missing_methods)
 
     allow(subject)
       .to receive(:association).with(any_args).and_return association
diff --git a/spec/factory_bot/attribute/dynamic_spec.rb b/spec/factory_bot/attribute/dynamic_spec.rb
index 60cfe09..bec6627 100644
--- a/spec/factory_bot/attribute/dynamic_spec.rb
+++ b/spec/factory_bot/attribute/dynamic_spec.rb
@@ -26,15 +26,14 @@ describe FactoryBot::Attribute::Dynamic do
     let(:block) { -> { attribute_defined_on_attribute } }
     let(:result) { "other attribute value" }
 
-    module MissingMethods
-      def attribute_defined_on_attribute(*args)
-      end
-    end
-
     before do
       # Define an '#attribute_defined_on_attribute' instance method allowing it
       # be mocked. Ususually this is determined via '#method_missing'
-      subject.extend(MissingMethods)
+      missing_methods = Module.new {
+        def attribute_defined_on_attribute(*args)
+        end
+      }
+      subject.extend(missing_methods)
 
       allow(subject)
         .to receive(:attribute_defined_on_attribute).and_return result
diff --git a/spec/support/macros/define_constant.rb b/spec/support/macros/define_constant.rb
index b8c4b10..2621dd1 100644
--- a/spec/support/macros/define_constant.rb
+++ b/spec/support/macros/define_constant.rb
@@ -3,7 +3,7 @@ require "active_record"
 module DefineConstantMacros
   def define_class(path, base = Object, &block)
     const = stub_const(path, Class.new(base))
-    const.class_eval(&block) if block_given?
+    const.class_eval(&block) if block
     const
   end