diff --git a/Gemfile.lock b/Gemfile.lock
index 4e5bbdf..20d0f56 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     apple_card_statement_parser (0.1.0)
-      json (~> 2.1.0)
+      json (>= 2.1, < 2.4)
       pdf-reader (~> 2.2.1)
 
 GEM
@@ -13,7 +13,7 @@ GEM
     coderay (1.1.2)
     diff-lcs (1.3)
     hashery (2.1.2)
-    json (2.1.0)
+    json (2.3.1)
     method_source (0.9.2)
     pdf-reader (2.2.1)
       Ascii85 (~> 1.0.0)
@@ -39,7 +39,7 @@ GEM
       rspec-support (~> 3.9.0)
     rspec-support (3.9.0)
     ruby-rc4 (0.1.5)
-    ttfunk (1.5.1)
+    ttfunk (1.6.2.1)
 
 PLATFORMS
   ruby
diff --git a/apple_card_statement_parser.gemspec b/apple_card_statement_parser.gemspec
index e3e32a9..8235ffc 100644
--- a/apple_card_statement_parser.gemspec
+++ b/apple_card_statement_parser.gemspec
@@ -22,7 +22,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_runtime_dependency "pdf-reader", "~> 2.2.1"
-  spec.add_runtime_dependency "json", "~> 2.1.0"
+  spec.add_runtime_dependency "json", ">= 2.1", "< 2.4"
 
   spec.add_development_dependency "bundler", "~> 1.17"
   spec.add_development_dependency "rake", "~> 13.0"