diff --git a/activerecord/lib/active_record/attribute_set/builder.rb b/activerecord/lib/active_record/attribute_set/builder.rb
index 05138ae36d..3a76f5262d 100644
--- a/activerecord/lib/active_record/attribute_set/builder.rb
+++ b/activerecord/lib/active_record/attribute_set/builder.rb
@@ -76,7 +76,9 @@ module ActiveRecord
       unless @materialized
         values.each_key { |key| self[key] }
         types.each_key { |key| self[key] }
-        @materialized = true
+        unless frozen?
+          @materialized = true
+        end
       end
       delegate_hash
     end
diff --git a/activerecord/test/cases/attribute_set_test.rb b/activerecord/test/cases/attribute_set_test.rb
index de63672963..ba53612d30 100644
--- a/activerecord/test/cases/attribute_set_test.rb
+++ b/activerecord/test/cases/attribute_set_test.rb
@@ -178,5 +178,13 @@ module ActiveRecord
       builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
       builder.build_from_database(foo: '1.1')
     end
+
+    test "freezing doesn't prevent the set from materializing" do
+      builder = AttributeSet::Builder.new(foo: Type::String.new)
+      attributes = builder.build_from_database(foo: "1")
+
+      attributes.freeze
+      assert_equal({ foo: "1" }, attributes.to_hash)
+    end
   end
 end