diff --git a/lib/rubocop/cop/rails/helper_instance_variable.rb b/lib/rubocop/cop/rails/helper_instance_variable.rb
index 8e33d719e6..5cc3e2c3dd 100644
--- a/lib/rubocop/cop/rails/helper_instance_variable.rb
+++ b/lib/rubocop/cop/rails/helper_instance_variable.rb
@@ -16,12 +16,12 @@ module Rails
       # @example
       #   # bad
       #   def welcome_message
-      #     "Hello " + @user.name
+      #     "Hello #{@user.name}"
       #   end
       #
       #   # good
       #   def welcome_message(user)
-      #     "Hello " + user.name
+      #     "Hello #{user.name}"
       #   end
       class HelperInstanceVariable < Cop
         MSG = 'Do not use instance variables in helpers.'.freeze
diff --git a/manual/cops_rails.md b/manual/cops_rails.md
index 488adc81b1..4f690d0f21 100644
--- a/manual/cops_rails.md
+++ b/manual/cops_rails.md
@@ -825,12 +825,12 @@ example to a model, decorator or presenter.
 ```ruby
 # bad
 def welcome_message
-  "Hello " + @user.name
+  "Hello #{@user.name}"
 end
 
 # good
 def welcome_message(user)
-  "Hello " + user.name
+  "Hello #{user.name}"
 end
 ```