diff --git a/.travis.yml b/.travis.yml
index 9fa4e23..5fc561d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,8 @@ env:
       else git log -1 --skip 1 --pretty=format:%ct; fi)
 
 before_install:
-  - gem install bundler -v 2.0.1
+  - gem update --system
+  - gem install bundler
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
   - chmod +x ./cc-test-reporter
 
@@ -23,10 +24,16 @@ after_script:
   - if [[ "${COV}" = "true" ]]; then ./cc-test-reporter after-build --exit-code $TRAVIS_TEST_RESULT; fi;
 
 rvm:
+  - truffleruby
+  - rbx-3
   - 2.3.7
   - 2.4.5
 
 matrix:
+  allow_failures:
+    - truffleruby
+    - jruby
+    - rbx-3
   fast_finish: true
   include:
     - rvm: 2.5.3
diff --git a/Gemfile b/Gemfile
index 60377ea..f2efc31 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,4 +3,6 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in stub_requests.gemspec
 gemspec
 
-gem "rb-readline"
+platforms :mri_25 do
+  gem "rb-readline"
+end
diff --git a/gemfiles/webmock_2.3.gemfile b/gemfiles/webmock_2.3.gemfile
index 6dd7e16..83e0f23 100644
--- a/gemfiles/webmock_2.3.gemfile
+++ b/gemfiles/webmock_2.3.gemfile
@@ -2,7 +2,10 @@
 
 source "https://rubygems.org"
 
-gem "rb-readline"
 gem "webmock", "~> 2.3.0"
 
+platforms :mri_25 do
+  gem "rb-readline"
+end
+
 gemspec path: "../"
diff --git a/gemfiles/webmock_2.3.gemfile.lock b/gemfiles/webmock_2.3.gemfile.lock
index bc48d36..f9e4fc8 100644
--- a/gemfiles/webmock_2.3.gemfile.lock
+++ b/gemfiles/webmock_2.3.gemfile.lock
@@ -1,10 +1,10 @@
 PATH
   remote: ..
   specs:
-    stub_requests (0.1.2)
-      concurrent-ruby (~> 1.0, < 2)
-      docile (~> 1.0, < 2)
-      public_suffix (~> 3.0, < 4)
+    stub_requests (0.1.3)
+      concurrent-ruby (>= 1.0, < 2.0)
+      docile (>= 1.0, < 2.0)
+      public_suffix (>= 3.0, < 4.0)
       webmock (>= 2.3, < 4.0)
 
 GEM
@@ -45,7 +45,7 @@ GEM
       multipart-post (>= 1.2, < 3)
     faraday-http-cache (2.0.0)
       faraday (~> 0.8)
-    faraday_middleware (0.13.0)
+    faraday_middleware (0.13.1)
       faraday (>= 0.7.4, < 1.0)
     ffi (1.10.0)
     gem-release (2.0.1)
@@ -180,25 +180,25 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  appraisal (>= 2.2.0)
-  bundler (>= 2.0)
-  gem-release (>= 2.0)
+  appraisal (>= 2.2.0, < 3.0)
+  bundler (>= 1.7, < 3.0)
+  gem-release (>= 2.0, < 4.0)
   github-markup (~> 3.0)
   github_changelog_generator (~> 1.14)
-  json_spec (>= 1.1.5)
-  pry (>= 0.12)
-  rake (>= 10.0)
+  json_spec (>= 1.1.5, < 2.0)
+  pry (>= 0.12, < 3.0)
+  rake (>= 10.0, < 15.0)
   rb-readline
   redcarpet (~> 3.4)
-  reek (>= 5.0)
-  rspec (>= 3.8)
-  rspec-its (>= 1.2)
-  rubocop (~> 0.63.1)
-  rubocop-rspec (~> 1.32)
-  simplecov (>= 0.16.1)
-  simplecov-json (>= 0.2)
+  reek (~> 5.0, < 6.0)
+  rspec (>= 3.8, < 5.0)
+  rspec-its (>= 1.2, < 5.0)
+  rubocop (~> 0.63, < 1.0)
+  rubocop-rspec (>= 1.32, < 3.0)
+  simplecov (>= 0.16, < 1.0)
+  simplecov-json (>= 0.2, < 2.0)
   stub_requests!
-  travis (>= 1.8.9)
+  travis (>= 1.8.9, < 3.0)
   webmock (~> 2.3.0)
   yard (~> 0.9.18)
 
diff --git a/gemfiles/webmock_3.5.gemfile b/gemfiles/webmock_3.5.gemfile
index 947c28b..4c1559a 100644
--- a/gemfiles/webmock_3.5.gemfile
+++ b/gemfiles/webmock_3.5.gemfile
@@ -2,7 +2,10 @@
 
 source "https://rubygems.org"
 
-gem "rb-readline"
 gem "webmock", "~> 3.5.0"
 
+platforms :mri_25 do
+  gem "rb-readline"
+end
+
 gemspec path: "../"
diff --git a/gemfiles/webmock_3.5.gemfile.lock b/gemfiles/webmock_3.5.gemfile.lock
index 565e290..0e58db8 100644
--- a/gemfiles/webmock_3.5.gemfile.lock
+++ b/gemfiles/webmock_3.5.gemfile.lock
@@ -1,10 +1,10 @@
 PATH
   remote: ..
   specs:
-    stub_requests (0.1.2)
-      concurrent-ruby (~> 1.0, < 2)
-      docile (~> 1.0, < 2)
-      public_suffix (~> 3.0, < 4)
+    stub_requests (0.1.3)
+      concurrent-ruby (>= 1.0, < 2.0)
+      docile (>= 1.0, < 2.0)
+      public_suffix (>= 3.0, < 4.0)
       webmock (>= 2.3, < 4.0)
 
 GEM
@@ -45,7 +45,7 @@ GEM
       multipart-post (>= 1.2, < 3)
     faraday-http-cache (2.0.0)
       faraday (~> 0.8)
-    faraday_middleware (0.13.0)
+    faraday_middleware (0.13.1)
       faraday (>= 0.7.4, < 1.0)
     ffi (1.10.0)
     gem-release (2.0.1)
@@ -180,25 +180,25 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  appraisal (>= 2.2.0)
-  bundler (>= 2.0)
-  gem-release (>= 2.0)
+  appraisal (>= 2.2.0, < 3.0)
+  bundler (>= 1.7, < 3.0)
+  gem-release (>= 2.0, < 4.0)
   github-markup (~> 3.0)
   github_changelog_generator (~> 1.14)
-  json_spec (>= 1.1.5)
-  pry (>= 0.12)
-  rake (>= 10.0)
+  json_spec (>= 1.1.5, < 2.0)
+  pry (>= 0.12, < 3.0)
+  rake (>= 10.0, < 15.0)
   rb-readline
   redcarpet (~> 3.4)
-  reek (>= 5.0)
-  rspec (>= 3.8)
-  rspec-its (>= 1.2)
-  rubocop (~> 0.63.1)
-  rubocop-rspec (~> 1.32)
-  simplecov (>= 0.16.1)
-  simplecov-json (>= 0.2)
+  reek (~> 5.0, < 6.0)
+  rspec (>= 3.8, < 5.0)
+  rspec-its (>= 1.2, < 5.0)
+  rubocop (~> 0.63, < 1.0)
+  rubocop-rspec (>= 1.32, < 3.0)
+  simplecov (>= 0.16, < 1.0)
+  simplecov-json (>= 0.2, < 2.0)
   stub_requests!
-  travis (>= 1.8.9)
+  travis (>= 1.8.9, < 3.0)
   webmock (~> 3.5.0)
   yard (~> 0.9.18)
 
diff --git a/gemfiles/webmock_develop.gemfile b/gemfiles/webmock_develop.gemfile
index 7dcd7a5..83edfe5 100644
--- a/gemfiles/webmock_develop.gemfile
+++ b/gemfiles/webmock_develop.gemfile
@@ -2,7 +2,10 @@
 
 source "https://rubygems.org"
 
-gem "rb-readline"
 gem "webmock", git: "https://github.com/bblimke/webmock.git"
 
+platforms :mri_25 do
+  gem "rb-readline"
+end
+
 gemspec path: "../"
diff --git a/gemfiles/webmock_develop.gemfile.lock b/gemfiles/webmock_develop.gemfile.lock
index 6277cae..ead19d0 100644
--- a/gemfiles/webmock_develop.gemfile.lock
+++ b/gemfiles/webmock_develop.gemfile.lock
@@ -10,10 +10,10 @@ GIT
 PATH
   remote: ..
   specs:
-    stub_requests (0.1.2)
-      concurrent-ruby (~> 1.0, < 2)
-      docile (~> 1.0, < 2)
-      public_suffix (~> 3.0, < 4)
+    stub_requests (0.1.3)
+      concurrent-ruby (>= 1.0, < 2.0)
+      docile (>= 1.0, < 2.0)
+      public_suffix (>= 3.0, < 4.0)
       webmock (>= 2.3, < 4.0)
 
 GEM
@@ -54,7 +54,7 @@ GEM
       multipart-post (>= 1.2, < 3)
     faraday-http-cache (2.0.0)
       faraday (~> 0.8)
-    faraday_middleware (0.13.0)
+    faraday_middleware (0.13.1)
       faraday (>= 0.7.4, < 1.0)
     ffi (1.10.0)
     gem-release (2.0.1)
@@ -185,25 +185,25 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  appraisal (>= 2.2.0)
-  bundler (>= 2.0)
-  gem-release (>= 2.0)
+  appraisal (>= 2.2.0, < 3.0)
+  bundler (>= 1.7, < 3.0)
+  gem-release (>= 2.0, < 4.0)
   github-markup (~> 3.0)
   github_changelog_generator (~> 1.14)
-  json_spec (>= 1.1.5)
-  pry (>= 0.12)
-  rake (>= 10.0)
+  json_spec (>= 1.1.5, < 2.0)
+  pry (>= 0.12, < 3.0)
+  rake (>= 10.0, < 15.0)
   rb-readline
   redcarpet (~> 3.4)
-  reek (>= 5.0)
-  rspec (>= 3.8)
-  rspec-its (>= 1.2)
-  rubocop (~> 0.63.1)
-  rubocop-rspec (~> 1.32)
-  simplecov (>= 0.16.1)
-  simplecov-json (>= 0.2)
+  reek (~> 5.0, < 6.0)
+  rspec (>= 3.8, < 5.0)
+  rspec-its (>= 1.2, < 5.0)
+  rubocop (~> 0.63, < 1.0)
+  rubocop-rspec (>= 1.32, < 3.0)
+  simplecov (>= 0.16, < 1.0)
+  simplecov-json (>= 0.2, < 2.0)
   stub_requests!
-  travis (>= 1.8.9)
+  travis (>= 1.8.9, < 3.0)
   webmock!
   yard (~> 0.9.18)
 
diff --git a/stub_requests.gemspec b/stub_requests.gemspec
index dcd1856..035bf89 100644
--- a/stub_requests.gemspec
+++ b/stub_requests.gemspec
@@ -30,31 +30,31 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "docile",          "~> 1.0", "< 2"
+  spec.add_dependency "docile",          ">= 1.0", "< 2.0"
   spec.add_dependency "webmock",         ">= 2.3", "< 4.0"
-  spec.add_dependency "concurrent-ruby", "~> 1.0", "< 2"
-  spec.add_dependency "public_suffix",   "~> 3.0", "< 4"
+  spec.add_dependency "concurrent-ruby", ">= 1.0", "< 2.0"
+  spec.add_dependency "public_suffix",   ">= 3.0", "< 4.0"
 
   # ===== Basics =====
-  spec.add_development_dependency "bundler",        ">= 2.0"
-  spec.add_development_dependency "rake",           ">= 10.0"
+  spec.add_development_dependency "bundler", ">= 1.7",  "< 3.0"
+  spec.add_development_dependency "rake",    ">= 10.0", "< 15.0"
 
   # ===== Testing =====
-  spec.add_development_dependency "appraisal",      ">= 2.2.0"
-  spec.add_development_dependency "json_spec",      ">= 1.1.5"
-  spec.add_development_dependency "rspec",          ">= 3.8"
-  spec.add_development_dependency "rspec-its",      ">= 1.2"
-  spec.add_development_dependency "rubocop",        "~> 0.63.1"
-  spec.add_development_dependency "rubocop-rspec",  "~> 1.32"
-  spec.add_development_dependency "simplecov",      ">= 0.16.1"
-  spec.add_development_dependency "simplecov-json", ">= 0.2"
-  spec.add_development_dependency "reek",           ">= 5.0"
+  spec.add_development_dependency "appraisal",      ">= 2.2.0", "< 3.0"
+  spec.add_development_dependency "json_spec",      ">= 1.1.5", "< 2.0"
+  spec.add_development_dependency "rspec",          ">= 3.8",   "< 5.0"
+  spec.add_development_dependency "rspec-its",      ">= 1.2",   "< 5.0"
+  spec.add_development_dependency "rubocop",        "~> 0.63",  "< 1.0"
+  spec.add_development_dependency "rubocop-rspec",  ">= 1.32",  "< 3.0"
+  spec.add_development_dependency "simplecov",      ">= 0.16",  "< 1.0"
+  spec.add_development_dependency "simplecov-json", ">= 0.2",   "< 2.0"
+  spec.add_development_dependency "reek",           "~> 5.0",   "< 6.0"
 
   # ===== Debugging  =====
-  spec.add_development_dependency "pry", ">= 0.12"
+  spec.add_development_dependency "pry", ">= 0.12", "< 3.0"
 
   # ===== Utilities =====
-  spec.add_development_dependency "travis", ">= 1.8.9"
+  spec.add_development_dependency "travis", ">= 1.8.9", "< 3.0"
 
   # ===== Documentation =====
   spec.add_development_dependency "yard",          "~> 0.9.18"
@@ -63,5 +63,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "github_changelog_generator", "~> 1.14"
 
   # ===== Release Management =====
-  spec.add_development_dependency "gem-release", ">= 2.0"
+  spec.add_development_dependency "gem-release", ">= 2.0", "< 4.0"
 end