diff --git a/Gemfile.lock b/Gemfile.lock
index 53563a88..0999eeac 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,7 +3,7 @@ PATH
   specs:
     xero-ruby (18.1.0)
       faraday (>= 2.0, < 3.0)
-      json (~> 2.1, >= 2.1.0)
+      json (>= 2.1.0, < 4)
       json-jwt (~> 1.16, >= 1.16.3)
 
 GEM
diff --git a/xero-ruby.gemspec b/xero-ruby.gemspec
index 2662de90..c6e45ad6 100644
--- a/xero-ruby.gemspec
+++ b/xero-ruby.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = ">= 2.3"
 
   s.add_runtime_dependency 'faraday', '>= 2.0', '< 3.0'
-  s.add_runtime_dependency 'json', '~> 2.1', '>= 2.1.0'
+  s.add_runtime_dependency 'json', '>= 2.1.0', '< 4'
   s.add_runtime_dependency 'json-jwt', '~> 1.16', '>= 1.16.3'
   s.add_development_dependency 'rspec', '~> 3.6', '>= 3.6.0'