diff --git a/lib/omniauth/strategies/discourse/sso.rb b/lib/omniauth/strategies/discourse/sso.rb
index 327a026..2d8e3be 100644
--- a/lib/omniauth/strategies/discourse/sso.rb
+++ b/lib/omniauth/strategies/discourse/sso.rb
@@ -65,7 +65,7 @@ def base64_encoded_payload
           end
 
           def url_encoded_payload
-            URI.escape(base64_encoded_payload)
+            CGI.escape(base64_encoded_payload)
           end
 
           def hex_signature
@@ -83,4 +83,4 @@ def base64? data
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/omniauth-discourse.gemspec b/omniauth-discourse.gemspec
index 5b81f61..36a5ab8 100644
--- a/omniauth-discourse.gemspec
+++ b/omniauth-discourse.gemspec
@@ -8,7 +8,7 @@ Gem::Specification.new do |gem|
   gem.homepage      = "https://github.com/lackstein/omniauth-discourse"
   gem.license       = "MIT"
 
-  gem.add_dependency "omniauth", "~> 1.0"
+  gem.add_dependency "omniauth", ">= 1.0", "< 3"
   gem.add_development_dependency "bundler", "~> 1.9"
 
   gem.executables   = `git ls-files -- bin/*`.split("\n").map { |f| File.basename(f) }