diff --git a/jquery-rails.gemspec b/jquery-rails.gemspec
index 737c577f..564eff57 100644
--- a/jquery-rails.gemspec
+++ b/jquery-rails.gemspec
@@ -15,7 +15,7 @@ Gem::Specification.new do |s|
   s.rubyforge_project         = "jquery-rails"
 
   s.add_dependency "railties", ">= 3.0", "< 5.0"
-  s.add_dependency "thor",     ">= 0.14"
+  s.add_dependency "thor",     ">= 0.14", "< 2.0"
 
   s.files        = `git ls-files`.split("\n")
   s.executables  = `git ls-files -- bin/*`.split("\n").map { |f| File.basename(f) }