diff --git a/lib/vaporizer.rb b/lib/vaporizer.rb
index 9f6ffc8..b901f96 100644
--- a/lib/vaporizer.rb
+++ b/lib/vaporizer.rb
@@ -45,16 +45,11 @@ def local_or_external_path(path)
     def match_substitute(string, match)
       string.gsub(/\$([`&0-9'$])/) do |sub|
         case $1
-        when "`" 
-          match.pre_match
-        when "&"
-          match[0]
-        when "0".."9"
-          match[$1.to_i]
-        when "'" 
-          match.post_match
-        when "$"
-          '$'
+        when "`" then match.pre_match
+        when "&" then match[0]
+        when "0".."9" then match[$1.to_i]
+        when "'" then match.post_match
+        when "$" then '$'
         end
       end
     end