diff --git a/Library/.rubocop.yml b/Library/.rubocop.yml
index 64aee5590b..8b9a828c09 100644
--- a/Library/.rubocop.yml
+++ b/Library/.rubocop.yml
@@ -9,6 +9,7 @@ inherit_mode:
   merge:
     - Include
     - Exclude
+    - AllowedMethods
 
 AllCops:
   TargetRubyVersion: 2.6
diff --git a/Library/Homebrew/.rubocop.yml b/Library/Homebrew/.rubocop.yml
index 5eb3d467b7..4f0dd87d98 100644
--- a/Library/Homebrew/.rubocop.yml
+++ b/Library/Homebrew/.rubocop.yml
@@ -50,9 +50,7 @@ Metrics/ModuleLength:
     - "test/**/*"
 
 Naming/PredicateName:
-  # Can't rename these.
   AllowedMethods:
-    - is_a?
     - is_32_bit?
     - is_64_bit?