diff --git a/.travis.yml b/.travis.yml
index cfe3e7ab..32e84575 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,13 @@
 rvm:
-  - 1.9.3
-  - 2.0.0
+  - 1.9
+  - 2.0
   - 2.1
-  - 2.1.1
   - jruby-19mode
   - jruby-head
-  - rbx-19mode
+  - rbx-2
 matrix:
   allow_failures:
-    - rvm: rbx-19mode
+    - rvm: rbx-2
     - rvm: jruby-head
 
 script: "rake test"
diff --git a/Gemfile b/Gemfile
index fa75df15..05cbb03e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,4 @@
 source 'https://rubygems.org'
 
 gemspec
+gem 'stackprof', platforms: :mri_21
diff --git a/liquid.gemspec b/liquid.gemspec
index 1b0ae1ed..0cd2f86a 100644
--- a/liquid.gemspec
+++ b/liquid.gemspec
@@ -24,6 +24,5 @@ Gem::Specification.new do |s|
 
   s.require_path = "lib"
 
-  s.add_development_dependency 'stackprof' if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new("2.1.0")
   s.add_development_dependency 'rake'
 end