diff --git a/lib/mongoid/enum/configuration.rb b/lib/mongoid/enum/configuration.rb
index 63a2e82..ed45df4 100644
--- a/lib/mongoid/enum/configuration.rb
+++ b/lib/mongoid/enum/configuration.rb
@@ -4,7 +4,7 @@ module Mongoid
       attr_accessor :field_name_prefix
 
       def initialize
-        self.field_name_prefix = '_'
+        self.field_name_prefix = "_"
       end
     end
 
diff --git a/spec/mongoid/configuration_spec.rb b/spec/mongoid/configuration_spec.rb
index 9ce7987..db04d68 100644
--- a/spec/mongoid/configuration_spec.rb
+++ b/spec/mongoid/configuration_spec.rb
@@ -5,7 +5,7 @@ describe Mongoid::Enum::Configuration do
 
   describe "field_name_prefix" do
     it "has '_' as default value" do
-      expect(subject.field_name_prefix).to eq '_'
+      expect(subject.field_name_prefix).to eq "_"
     end
   end
 end
diff --git a/spec/mongoid/enum_spec.rb b/spec/mongoid/enum_spec.rb
index 1b70998..e551df2 100644
--- a/spec/mongoid/enum_spec.rb
+++ b/spec/mongoid/enum_spec.rb
@@ -25,7 +25,7 @@ describe Mongoid::Enum do
     it "uses prefix defined in configuration" do
       old_field_name_prefix = Mongoid::Enum.configuration.field_name_prefix
       Mongoid::Enum.configure do |config|
-        config.field_name_prefix = '___'
+        config.field_name_prefix = "___"
       end
       UserWithoutPrefix = Class.new do
         include Mongoid::Document
@@ -33,7 +33,7 @@ describe Mongoid::Enum do
 
         enum :status, [:awaiting_approval, :approved, :banned]
       end
-      expect(UserWithoutPrefix).to have_field '___status'
+      expect(UserWithoutPrefix).to have_field "___status"
       Mongoid::Enum.configure do |config|
         config.field_name_prefix = old_field_name_prefix
       end
@@ -195,7 +195,8 @@ describe Mongoid::Enum do
 
   describe ".configuration" do
     it "returns Configuration object" do
-      expect(Mongoid::Enum.configuration).to be_instance_of Mongoid::Enum::Configuration
+      expect(Mongoid::Enum.configuration)
+          .to be_instance_of Mongoid::Enum::Configuration
     end
     it "returns same object when called multiple times" do
       expect(Mongoid::Enum.configuration).to be Mongoid::Enum.configuration
@@ -204,7 +205,8 @@ describe Mongoid::Enum do
 
   describe ".configure" do
     it "yields configuration if block is given" do
-      expect { |b| Mongoid::Enum.configure &b }.to yield_with_args Mongoid::Enum.configuration
+      expect { |b| Mongoid::Enum.configure &b }
+          .to yield_with_args Mongoid::Enum.configuration
     end
   end
 end