diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8ba464c..1d187b0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## 3.0.0 [unreleased]
 
 - Removed support for Elasticsearch 2
+- Removed support for ActiveRecord < 4.2
 - Removed `reindex_async` method. `reindex` now defaults to mode specified by model. Use `reindex(mode: :async)` to force async reindex.
 
 ## 2.5.1 [unreleased]
diff --git a/README.md b/README.md
index b172e77..26649e3 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ Add this line to your application’s Gemfile:
 gem 'searchkick'
 ```
 
-The latest version works with Elasticsearch 2, 5, and 6. For Elasticsearch 1, use version 1.5.1 and [this readme](https://github.com/ankane/searchkick/blob/v1.5.1/README.md).
+The latest version works with Elasticsearch 5 and 6. For Elasticsearch 2, use version 2.5.0 and [this readme](https://github.com/ankane/searchkick/blob/v2.5.0/README.md).
 
 Add searchkick to models you want to search.
 
@@ -1093,12 +1093,6 @@ heroku run rake searchkick:reindex CLASS=Product
 
 ### Amazon Elasticsearch Service
 
-Include `elasticsearch 1.0.15` or greater in your Gemfile.
-
-```ruby
-gem 'elasticsearch', '>= 1.0.15'
-```
-
 Create an initializer `config/initializers/elasticsearch.rb` with:
 
 ```ruby
@@ -1108,7 +1102,7 @@ ENV["ELASTICSEARCH_URL"] = "https://es-domain-1234.us-east-1.es.amazonaws.com"
 To use signed request, include in your Gemfile:
 
 ```ruby
-gem 'faraday_middleware-aws-signers-v4', '>= 0.1.9'
+gem 'faraday_middleware-aws-sigv4'
 ```
 
 and add to your initializer:
diff --git a/searchkick.gemspec b/searchkick.gemspec
index 1e404e4..c007d0a 100644
--- a/searchkick.gemspec
+++ b/searchkick.gemspec
@@ -18,11 +18,11 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features|benchmark)/})
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "activemodel", ">= 4.1"
-  spec.add_dependency "elasticsearch", ">= 1"
+  spec.add_dependency "activemodel", ">= 4.2"
+  spec.add_dependency "elasticsearch", ">= 5"
   spec.add_dependency "hashie"
 
   spec.add_development_dependency "bundler"
-  spec.add_development_dependency "rake"
   spec.add_development_dependency "minitest"
+  spec.add_development_dependency "rake"
 end
--
libgit2 0.21.0