diff --git a/Formula/php@7.1.rb b/Formula/php@7.1.rb
index 89ae1a3389..71220e1cd3 100644
--- a/Formula/php@7.1.rb
+++ b/Formula/php@7.1.rb
@@ -242,7 +242,7 @@ class PhpAT71 < Formula
       "test_dir" => pear_path/"test",
       "php_bin"  => opt_bin/"php",
     }.each do |key, value|
-      value.mkpath if key =~ /(?<!bin|man)_dir$/
+      value.mkpath if /(?<!bin|man)_dir$/.match?(key)
       system bin/"pear", "config-set", key, value, "system"
     end