diff --git a/Appraisals b/Appraisals
index 70246973..17dcf10b 100644
--- a/Appraisals
+++ b/Appraisals
@@ -4,14 +4,26 @@ end
 
 appraise 'rails-4.0' do
   gem 'rails', '~> 4.0.0'
+
+  # The last version that doesn't need Ruby 2.0 and works with version 4.0 of
+  # Rails. This addresses a build problem with Travis for version 1.9.3 of Ruby
+  gem 'mime-types', '2.6.2', :platforms => :ruby_19
 end
 
 appraise 'rails-4.1' do
   gem 'rails', '~> 4.1.0'
+
+  # The last version that doesn't need Ruby 2.0 and works with version 4.1 of
+  # Rails. This addresses a build problem with Travis for version 1.9.3 of Ruby
+  gem 'mime-types', '2.6.2', :platforms => :ruby_19
 end
 
 appraise 'rails-4.2' do
   gem 'rails', '~> 4.2.0'
+
+  # The last version that doesn't need Ruby 2.0 and works with version 4.2 of
+  # Rails. This addresses a build problem with Travis for version 1.9.3 of Ruby
+  gem 'mime-types', '2.6.2', :platforms => :ruby_19
 end
 
 appraise 'mongoid-3.0' do
diff --git a/gemfiles/rails_4.0.gemfile b/gemfiles/rails_4.0.gemfile
index c6d0a1f1..f0da331f 100644
--- a/gemfiles/rails_4.0.gemfile
+++ b/gemfiles/rails_4.0.gemfile
@@ -3,5 +3,6 @@
 source "https://rubygems.org"
 
 gem "rails", "~> 4.0.0"
+gem "mime-types", "2.6.2", :platforms => :ruby_19
 
 gemspec :path => "../"
diff --git a/gemfiles/rails_4.1.gemfile b/gemfiles/rails_4.1.gemfile
index f95005cd..3ae2735f 100644
--- a/gemfiles/rails_4.1.gemfile
+++ b/gemfiles/rails_4.1.gemfile
@@ -3,5 +3,6 @@
 source "https://rubygems.org"
 
 gem "rails", "~> 4.1.0"
+gem "mime-types", "2.6.2", :platforms => :ruby_19
 
 gemspec :path => "../"
diff --git a/gemfiles/rails_4.2.gemfile b/gemfiles/rails_4.2.gemfile
index cd8b45b1..2fb73f1d 100644
--- a/gemfiles/rails_4.2.gemfile
+++ b/gemfiles/rails_4.2.gemfile
@@ -3,5 +3,6 @@
 source "https://rubygems.org"
 
 gem "rails", "~> 4.2.0"
+gem "mime-types", "2.6.2", :platforms => :ruby_19
 
 gemspec :path => "../"