diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 9595d2a0efcd2830809ea67fd9afd91b5d8e4890..b954738ff2784aa2e8d9ddfd6f95fe3216990f3c 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -415,7 +415,7 @@ def test_generator_if_skip_action_cable_is_given
 
   def test_action_cable_redis_gems
     run_generator
-    assert_gem 'redis'
+    assert_file "Gemfile", /^# gem 'redis'/
   end
 
   def test_inclusion_of_javascript_runtime