1 files changed, 5 insertions, 1 deletions
diff --git a/railties/lib/rails/application/default_middleware_stack.rb b/railties/lib/rails/application/default_middleware_stack.rb
index a00afe008c..d1789192ef 100644
--- a/railties/lib/rails/application/default_middleware_stack.rb
+++ b/railties/lib/rails/application/default_middleware_stack.rb
@@ -66,7 +66,11 @@ module Rails
         end
 
         def allow_concurrency?
-          config.allow_concurrency.nil? ? config.cache_classes : config.allow_concurrency
+          if config.allow_concurrency.nil?
+            config.cache_classes && config.eager_load
+          else
+            config.allow_concurrency
+          end
         end
 
         def load_rack_cache