diff --git a/Library/Homebrew/Gemfile b/Library/Homebrew/Gemfile
index 3d4f7e5298..2f231e18a7 100644
--- a/Library/Homebrew/Gemfile
+++ b/Library/Homebrew/Gemfile
@@ -15,6 +15,7 @@ end
 gem "bootsnap", require: false
 gem "byebug", require: false
 gem "json_schemer", require: false
+gem "method_source", require: false
 gem "minitest", require: false
 gem "parallel_tests", require: false
 gem "ronn", require: false
diff --git a/Library/Homebrew/Gemfile.lock b/Library/Homebrew/Gemfile.lock
index cca9c7e219..6044ab6fc2 100644
--- a/Library/Homebrew/Gemfile.lock
+++ b/Library/Homebrew/Gemfile.lock
@@ -233,6 +233,7 @@ DEPENDENCIES
   did_you_mean
   json_schemer
   mechanize
+  method_source
   minitest
   parallel_tests
   parlour