diff --git a/Gemfile b/Gemfile
index 8319f61..7b15f26 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,4 +15,4 @@ gem "tailwindcss-ruby", "~> 4.0", require: false
 # passes to JSON.parse, which breaks deserializing any serialized column.
 # Development only: applications pick their own json, and the incompatibility is
 # Rails', not this gem's.
-gem "json", "< 3"
+gem "json", "< 4"