[ci skip] When instance_reader is false, attribute can still be assigned by the instance objects

1 files changed, 2 insertions, 1 deletions

diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index 565c87c4b5..e0b6f2f820 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -954,7 +954,8 @@ class A
   class_attribute :x, instance_reader: false
 end
 
-A.new.x = 1 # NoMethodError
+A.new.x = 1
+A.new.x # NoMethodError
 ```
 
 For convenience `class_attribute` also defines an instance predicate which is the double negation of what the instance reader returns. In the examples above it would be called `x?`.