diff --git a/Gemfile.lock b/Gemfile.lock
index 1d069d3..c3955bb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     ione-rpc (1.0.0)
-      ione (~> 1)
+      ione (~> 1, >= 1.2)
 
 GEM
   remote: https://rubygems.org/
@@ -15,7 +15,7 @@ GEM
       thor
     diff-lcs (1.2.5)
     docile (1.1.3)
-    ione (1.1.4)
+    ione (1.2.0)
     mime-types (2.2)
     multi_json (1.9.2)
     rake (0.9.6)
diff --git a/ione-rpc.gemspec b/ione-rpc.gemspec
index 2ca7dfd..0fd3988 100644
--- a/ione-rpc.gemspec
+++ b/ione-rpc.gemspec
@@ -19,7 +19,7 @@ Gem::Specification.new do |s|
   s.test_files    = Dir['spec/**/*.rb']
   s.require_paths = %w(lib)
 
-  s.add_dependency 'ione', '~> 1'
+  s.add_runtime_dependency 'ione', '~> 1', '>= 1.2'
 
   s.platform = Gem::Platform::RUBY
   s.required_ruby_version = '>= 1.9.3'