diff --git a/dyndnsd.gemspec b/dyndnsd.gemspec
index 6d92f75..ec04e31 100644
--- a/dyndnsd.gemspec
+++ b/dyndnsd.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |s|
   s.executables = ['dyndnsd']
 
   s.add_runtime_dependency 'rack', '~> 1.6'
-  s.add_runtime_dependency 'json'
+  s.add_runtime_dependency 'json', '~> 1.8'
   s.add_runtime_dependency 'metriks'
 
   s.add_development_dependency 'bundler', '~> 1.3'