diff --git a/heroics.gemspec b/heroics.gemspec
index 0549177..da1f99f 100644
--- a/heroics.gemspec
+++ b/heroics.gemspec
@@ -14,6 +14,7 @@ Gem::Specification.new do |spec|
   spec.summary       = 'A Ruby client generator for HTTP APIs described with a JSON schema'
   spec.homepage      = 'https://github.com/interagent/heroics'
   spec.license       = 'MIT'
+  spec.required_ruby_version = '>= 2.5.0'
 
   spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features|example)/}) }
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
@@ -27,7 +28,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'yard'
   spec.add_development_dependency 'pry'
 
-  spec.add_dependency 'erubis', '~> 2.0'
   spec.add_dependency 'excon'
   spec.add_dependency 'multi_json', '>= 1.9.2'
   spec.add_dependency 'moneta'
diff --git a/lib/heroics.rb b/lib/heroics.rb
index e9a4ac5..a001178 100644
--- a/lib/heroics.rb
+++ b/lib/heroics.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 require 'base64'
-require 'erubis'
+require 'erb'
 require 'excon'
 require 'multi_json'
 require 'uri'
diff --git a/lib/heroics/client_generator.rb b/lib/heroics/client_generator.rb
index 1da1012..ab79cf0 100644
--- a/lib/heroics/client_generator.rb
+++ b/lib/heroics/client_generator.rb
@@ -4,12 +4,12 @@ module Heroics
   # option if you want to ship a gem or generate API documentation using Yard.
   def self.generate_client
     filename = File.dirname(__FILE__) + '/views/client.erb'
-    eruby = Erubis::Eruby.new(File.read(filename))
+    eruby = ERB.new(File.read(filename))
     context = build_context(Heroics::Configuration.defaults.module_name,
       Heroics::Configuration.defaults.schema,
       Heroics::Configuration.defaults.base_url,
       Heroics::Configuration.defaults.options)
-    eruby.evaluate(context)
+    eruby.result_with_hash(context)
   end
 
   private
diff --git a/lib/heroics/views/client.erb b/lib/heroics/views/client.erb
index 82ebf98..8815447 100644
--- a/lib/heroics/views/client.erb
+++ b/lib/heroics/views/client.erb
@@ -11,7 +11,7 @@ require 'heroics'
 require 'uri'
 require 'moneta'
 
-module <%= @module_name %>
+module <%= module_name %>
   # Get a Client configured to use HTTP Basic or header-based authentication.
   #
   # @param api_key [String] The API key to use when connecting.
@@ -75,7 +75,7 @@ module <%= @module_name %>
     if options[:default_headers]
       final_options[:default_headers].merge!(options[:default_headers])
     end
-    final_options[:cache] = options[:cache] || <%= @cache %>
+    final_options[:cache] = options[:cache] || <%= cache %>
     final_options[:url] = options[:url] if options[:url]
     final_options[:user] = options[:user] if options[:user]
     final_options
@@ -83,21 +83,21 @@ module <%= @module_name %>
 
   # Get the default options.
   def self.default_options
-    default_headers = <%= @default_headers %>
+    default_headers = <%= default_headers %>
     {
       default_headers: default_headers,
-      url:             "<%= @url %>"
+      url:             "<%= url %>"
     }
   end
 
   private_class_method :default_options, :custom_options
 
-  # <%= @description %>
+  # <%= description %>
   class Client
     def initialize(client)
       @client = client
     end
-    <% for resource in @resources %>
+    <% for resource in resources %>
 
     # <%= resource.description %>
     #
@@ -109,7 +109,7 @@ module <%= @module_name %>
   end
 
   private
-  <% for resource in @resources %>
+  <% for resource in resources %>
 
   # <%= resource.description %>
   class <%= resource.class_name %>
@@ -133,6 +133,6 @@ module <%= @module_name %>
   <% end %>
 
   SCHEMA = Heroics::Schema.new(MultiJson.load(<<-'HEROICS_SCHEMA'))
-<%= @schema %>
+<%= schema %>
 HEROICS_SCHEMA
 end