diff --git a/ls.rb b/ls.rb
index b9c3849..cf612ad 100644
--- a/ls.rb
+++ b/ls.rb
@@ -4,7 +4,7 @@ require 'optparse'
 require 'etc'
 
 COLUMNS = 3
-SIZE_INDENT = 3
+MARGIN = 3
 
 def run
   listed_filenames = list_filenames
@@ -84,7 +84,7 @@ def file_type(file_stat)
 end
 
 def file_size(filenames)
-  filenames.map { |file| File.size(file) }.max.to_s.length
+  filenames.map { |file| File.size(file) }.max.to_s.length + MARGIN
 end
 
 def timestamp(file_stat)