diff --git a/bin/markdown_ast.rb b/bin/markdown_ast.rb
index a88cd5f..c3fd0b5 100755
--- a/bin/markdown_ast.rb
+++ b/bin/markdown_ast.rb
@@ -3,7 +3,7 @@
 # Use Kramdown parser to produce AST for Markdown document.
 
 require "kramdown"
-require "json" 
+require "json"
 
 markdown = STDIN.read()
 doc = Kramdown::Document.new(markdown)