diff --git a/Gemfile.lock b/Gemfile.lock
index 0f4e1e5..32f3fa0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,11 +7,11 @@ GEM
     diff-lcs (1.1.3)
     gyoku (1.0.0)
       builder (>= 2.1.2)
-    httparty (0.10.0)
-      multi_json (~> 1.0)
-      multi_xml
-    multi_json (1.5.0)
-    multi_xml (0.5.2)
+    httparty (0.21.0)
+      mini_mime (>= 1.0.0)
+      multi_xml (>= 0.5.2)
+    mini_mime (1.1.2)
+    multi_xml (0.6.0)
     rake (12.3.3)
     rspec (2.12.0)
       rspec-core (~> 2.12.0)
diff --git a/fastspring-saasy.gemspec b/fastspring-saasy.gemspec
index cc4c2ce..787c013 100644
--- a/fastspring-saasy.gemspec
+++ b/fastspring-saasy.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
   s.require_paths = ["lib"]
   s.test_files    = s.files.grep(%r{^(test|spec|features)/})
 
-  s.add_dependency "httparty", "~> 0.10.0", ">= 0.10.0"
+  s.add_dependency "httparty", ">= 0.10", "< 0.22"
   s.add_dependency "gyoku", "~> 1.0.0", ">= 1.0.0"
 
   s.add_development_dependency "rake", ">= 10.0.3", "~> 12.3.3"