diff --git a/instapaper.gemspec b/instapaper.gemspec
index f241cb3..d0426ac 100644
--- a/instapaper.gemspec
+++ b/instapaper.gemspec
@@ -4,10 +4,10 @@ require 'instapaper/version'
 
 Gem::Specification.new do |spec|
   spec.add_dependency 'addressable', '~> 2.3'
-  spec.add_dependency 'http', '~> 0.7.1'
+  spec.add_dependency 'http', '~> 0.9'
   spec.add_dependency 'multi_json', '~> 1'
-  spec.add_dependency 'simple_oauth'
-  spec.add_dependency 'virtus'
+  spec.add_dependency 'simple_oauth', '~> 0.3'
+  spec.add_dependency 'virtus', '~> 1'
   spec.add_development_dependency 'bundler', '~> 1.0'
   spec.author        = 'Steve Agalloco'
   spec.description   = "Ruby Client for Instapaper's Full API"