diff --git a/actionview/test/template/url_helper_test.rb b/actionview/test/template/url_helper_test.rb
index bd38a67724..35fe3749ca 100644
--- a/actionview/test/template/url_helper_test.rb
+++ b/actionview/test/template/url_helper_test.rb
@@ -68,7 +68,7 @@ class UrlHelperTest < ActiveSupport::TestCase
 
   def test_url_for_with_back
     referer = "http://www.example.com/referer"
-    @controller = Struct.new(:request).new(Struct.new(:env).new("HTTP_REFERER" => referer))
+    @controller = Struct.new(:request).new(Struct.new(:env).new({ "HTTP_REFERER" => referer }))
 
     assert_equal "http://www.example.com/referer", url_for(:back)
   end
@@ -85,13 +85,13 @@ class UrlHelperTest < ActiveSupport::TestCase
 
   def test_url_for_with_back_and_javascript_referer
     referer = "javascript:alert(document.cookie)"
-    @controller = Struct.new(:request).new(Struct.new(:env).new("HTTP_REFERER" => referer))
+    @controller = Struct.new(:request).new(Struct.new(:env).new({ "HTTP_REFERER" => referer }))
     assert_equal "javascript:history.back()", url_for(:back)
   end
 
   def test_url_for_with_invalid_referer
     referer = "THIS IS NOT A URL"
-    @controller = Struct.new(:request).new(Struct.new(:env).new("HTTP_REFERER" => referer))
+    @controller = Struct.new(:request).new(Struct.new(:env).new({ "HTTP_REFERER" => referer }))
     assert_equal "javascript:history.back()", url_for(:back)
   end
 
diff --git a/activerecord/test/cases/arel/support/fake_record.rb b/activerecord/test/cases/arel/support/fake_record.rb
index 864f47e245..205bdeb41b 100644
--- a/activerecord/test/cases/arel/support/fake_record.rb
+++ b/activerecord/test/cases/arel/support/fake_record.rb
@@ -89,7 +89,7 @@ module FakeRecord
   end
 
   class ConnectionPool
-    class Spec < Struct.new(:config)
+    class Spec < Struct.new(:adapter, keyword_init: true)
     end
 
     attr_reader :spec, :connection
diff --git a/activerecord/test/cases/type/adapter_specific_registry_test.rb b/activerecord/test/cases/type/adapter_specific_registry_test.rb
index b58bdd5549..1093c4feca 100644
--- a/activerecord/test/cases/type/adapter_specific_registry_test.rb
+++ b/activerecord/test/cases/type/adapter_specific_registry_test.rb
@@ -76,7 +76,6 @@ module ActiveRecord
     end
 
     test "construct args are passed to the type" do
-      type = Struct.new(:args)
       registry = Type::AdapterSpecificRegistry.new
       registry.register(:foo, type)
 
@@ -117,7 +116,6 @@ module ActiveRecord
 
     test "registering adapter specific modifiers" do
       decoration = Struct.new(:value)
-      type = Struct.new(:args)
       registry = Type::AdapterSpecificRegistry.new
       registry.register(:foo, type)
       registry.add_modifier({ array: true }, decoration, adapter: :postgresql)
@@ -131,5 +129,17 @@ module ActiveRecord
         registry.lookup(:foo, array: true, adapter: :sqlite3)
       )
     end
+
+    TYPE = Class.new do
+      attr_reader :args
+
+      def initialize(args = nil)
+        @args = args
+      end
+
+      def ==(other) self.args == other.args end
+    end
+
+    private def type; TYPE end
   end
 end