diff --git a/Library/.rubocop_todo.yml b/Library/.rubocop_todo.yml
index 2f522a8fd6..fde1d853fb 100644
--- a/Library/.rubocop_todo.yml
+++ b/Library/.rubocop_todo.yml
@@ -86,12 +86,6 @@ Metrics/ModuleLength:
 Metrics/ParameterLists:
   Max: 6
 
-# Offense count: 2
-Performance/FixedSize:
-  Exclude:
-    - 'Homebrew/dev-cmd/audit.rb'
-    - 'Homebrew/dev-cmd/bottle.rb'
-
 # Offense count: 8
 Style/AccessorMethodName:
   Exclude:
diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 20e9a8aff0..55f545d0cd 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -467,7 +467,7 @@ class FormulaAuditor
 
     # Make sure the formula name plus description is no longer than 80 characters
     # Note full_name includes the name of the tap, while name does not
-    linelength = formula.name.length + ": ".length + desc.length
+    linelength = "#{formula.name}: #{desc}".length
     if linelength > 80
       problem <<-EOS.undent
         Description is too long. \"name: desc\" should be less than 80 characters.
diff --git a/Library/Homebrew/dev-cmd/bottle.rb b/Library/Homebrew/dev-cmd/bottle.rb
index f4d6a463af..fe07526f3f 100644
--- a/Library/Homebrew/dev-cmd/bottle.rb
+++ b/Library/Homebrew/dev-cmd/bottle.rb
@@ -436,7 +436,7 @@ module Homebrew
             puts output
             update_or_add = "add"
             if s.include? "stable do"
-              indent = s.slice(/^ +stable do/).length - "stable do".length
+              indent = s.slice(/^( +)stable do/, 1).length
               string = s.sub!(/^ {#{indent}}stable do(.|\n)+?^ {#{indent}}end\n/m, '\0' + output + "\n")
             else
               string = s.sub!(