diff --git a/Library/Homebrew/tap.rb b/Library/Homebrew/tap.rb
index c3fbc5f733da8..19a9cc2a23ce9 100644
--- a/Library/Homebrew/tap.rb
+++ b/Library/Homebrew/tap.rb
@@ -1337,6 +1337,7 @@ def tap_migrations
 
 # Permanent configuration per {Tap} using `git-config(1)`.
 class TapConfig
+  sig { returns(Tap) }
   attr_reader :tap
 
   sig { params(tap: Tap).void }
@@ -1344,6 +1345,7 @@ def initialize(tap)
     @tap = tap
   end
 
+  sig { params(key: T.any(Symbol, String)).returns(T.nilable(String)) }
   def [](key)
     return unless tap.git?
     return unless Utils::Git.available?
@@ -1351,6 +1353,7 @@ def [](key)
     Homebrew::Settings.read key, repo: tap.path
   end
 
+  sig { params(key: T.any(Symbol, String), value: T.any(T::Boolean, String)).void }
   def []=(key, value)
     return unless tap.git?
     return unless Utils::Git.available?
@@ -1358,6 +1361,7 @@ def []=(key, value)
     Homebrew::Settings.write key, value.to_s, repo: tap.path
   end
 
+  sig { params(key: T.any(Symbol, String)).void }
   def delete(key)
     return unless tap.git?
     return unless Utils::Git.available?