diff --git a/Library/Homebrew/debrew.rb b/Library/Homebrew/debrew.rb
index 53f2e3d51f..661d9e7428 100644
--- a/Library/Homebrew/debrew.rb
+++ b/Library/Homebrew/debrew.rb
@@ -1,4 +1,4 @@
-# typed: false
+# typed: true
 # frozen_string_literal: true
 
 require "mutex_m"
@@ -47,7 +47,7 @@ module Debrew
       menu = new
       yield menu
 
-      choice = nil
+      choice = T.let(nil, T.nilable(Entry))
       while choice.nil?
         menu.entries.each_with_index { |e, i| puts "#{i + 1}. #{e.name}" }
         print menu.prompt unless menu.prompt.nil?
@@ -90,7 +90,7 @@ module Debrew
       yield
     rescue SystemExit
       raise
-    rescue Exception => e # rubocop:disable Lint/RescueException
+    rescue Ignorable::ExceptionMixin => e
       e.ignore if debug(e) == :ignore # execution jumps back to where the exception was thrown
     ensure
       Ignorable.unhook_raise
@@ -99,7 +99,7 @@ module Debrew
   end
 
   def self.debug(exception)
-    raise(exception) if !active? || !debugged_exceptions.add?(exception) || !try_lock
+    raise(exception) if !active? || !debugged_exceptions.add?(exception) || !mu_try_lock
 
     begin
       puts exception.backtrace.first.to_s
@@ -119,7 +119,7 @@ module Debrew
               set_trace_func proc { |event, _, _, id, binding, klass|
                 if klass == Object && id == :raise && event == "return"
                   set_trace_func(nil)
-                  synchronize { IRB.start_within(binding) }
+                  mu_synchronize { IRB.start_within(binding) }
                 end
               }
 
@@ -134,7 +134,7 @@ module Debrew
         end
       end
     ensure
-      unlock
+      mu_unlock
     end
   end
 end
diff --git a/Library/Homebrew/dev-cmd/update-test.rb b/Library/Homebrew/dev-cmd/update-test.rb
index 8bb643b21c..4c92356af5 100644
--- a/Library/Homebrew/dev-cmd/update-test.rb
+++ b/Library/Homebrew/dev-cmd/update-test.rb
@@ -54,7 +54,7 @@ module Homebrew
     start_commit = T.let("", T.untyped)
     end_commit = "HEAD"
     cd HOMEBREW_REPOSITORY do
-      start_commit = if (commit = T.let(args.commit, T.nilable(String)))
+      start_commit = if (commit = args.commit)
         commit
       elsif (date = args.before)
         Utils.popen_read("git", "rev-list", "-n1", "--before=#{date}", "origin/master").chomp
diff --git a/Library/Homebrew/ignorable.rb b/Library/Homebrew/ignorable.rb
index 5aeeb4dc02..43a7d0af34 100644
--- a/Library/Homebrew/ignorable.rb
+++ b/Library/Homebrew/ignorable.rb
@@ -1,4 +1,4 @@
-# typed: false
+# typed: true
 # frozen_string_literal: true
 
 require "warnings"
@@ -30,7 +30,7 @@ module Ignorable
         rescue Exception => e # rubocop:disable Lint/RescueException
           unless e.is_a?(ScriptError)
             e.extend(ExceptionMixin)
-            e.continuation = continuation
+            T.cast(e, ExceptionMixin).continuation = continuation
           end
           super(e)
         end
@@ -47,7 +47,6 @@ module Ignorable
 
   def self.unhook_raise
     Object.class_eval do
-      # False positive - https://github.com/rubocop/rubocop/issues/5022
       alias_method :raise, :original_raise
       alias_method :fail, :original_raise
       undef :original_raise
diff --git a/Library/Homebrew/ignorable.rbi b/Library/Homebrew/ignorable.rbi
new file mode 100644
index 0000000000..f8b29fefac
--- /dev/null
+++ b/Library/Homebrew/ignorable.rbi
@@ -0,0 +1,8 @@
+# typed: strict
+
+module Ignorable
+  include Kernel
+  # This is a workaround to enable `raise` to be aliased
+  # @see https://github.com/sorbet/sorbet/issues/2378#issuecomment-569474238
+  def self.raise(*); end
+end
diff --git a/Library/Homebrew/sorbet/rbi/upstream.rbi b/Library/Homebrew/sorbet/rbi/upstream.rbi
new file mode 100644
index 0000000000..5d1e457f44
--- /dev/null
+++ b/Library/Homebrew/sorbet/rbi/upstream.rbi
@@ -0,0 +1,32 @@
+# typed: strict
+
+# This file contains temporary definitions for fixes that have
+# been submitted upstream to https://github.com/sorbet/sorbet.
+
+module Kernel
+  # @see https://github.com/sorbet/sorbet/blob/a1e8389/rbi/core/kernel.rbi#L41-L46
+  sig do
+    type_parameters(:U).params(
+      block: T.proc.params(cont: Continuation).returns(T.type_parameter(:U))
+    ).returns(T.type_parameter(:U))
+  end
+  def callcc(&block); end
+
+  # @see https://github.com/sorbet/sorbet/blob/a1e8389/rbi/core/kernel.rbi#L2348-L2363
+  sig do
+    params(
+      arg0: T.nilable(
+        T.proc.params(
+          event: String,
+          file: String,
+          line: Integer,
+          id: T.nilable(Symbol),
+          binding: T.nilable(Binding),
+          classname: Object,
+        ).returns(T.untyped)
+      )
+    ).void
+  end
+  sig { params(arg0: NilClass).returns(NilClass) }
+  def set_trace_func(arg0); end
+end