diff --git a/examples/dummy_app/Gemfile b/examples/dummy_app/Gemfile
index 0008648..257c081 100644
--- a/examples/dummy_app/Gemfile
+++ b/examples/dummy_app/Gemfile
@@ -1,5 +1,5 @@
 source "https://rubygems.org"
 
-gem "json", "~> 2.21"
+gem "json", "~> 3.0"
 gem "puma", "~> 8.0"
 gem "sinatra", "~> 4.2"
diff --git a/examples/dummy_app/Gemfile.lock b/examples/dummy_app/Gemfile.lock
index cbec08d..2da0d61 100644
--- a/examples/dummy_app/Gemfile.lock
+++ b/examples/dummy_app/Gemfile.lock
@@ -2,7 +2,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     base64 (0.3.0)
-    json (2.21.2)
+    json (3.0.2)
     logger (1.7.0)
     mustermann (3.1.1)
     nio4r (2.7.5)
@@ -30,7 +30,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  json (~> 2.21)
+  json (~> 3.0)
   puma (~> 8.0)
   sinatra (~> 4.2)