diff --git a/inject.rb b/inject.rb
index 9ed9128..23fe4fe 100755
--- a/inject.rb
+++ b/inject.rb
@@ -3,6 +3,7 @@
 require 'rubygems'
 require 'json'
 require 'fileutils'
+require 'stringio'
 
 def inject
   FileUtils.cp_r(mojo_ext_path, target_mojo_ext_path)
@@ -27,9 +28,15 @@ def sources_file
 end
 
 def save_sources!
+  # capture pretty-print output to string
+  pretty_json = StringIO.new
+  orig_stdout = $stdout
+  $stdout = pretty_json
+  jj sources
+  $stdout = orig_stdout
+  pretty_json.rewind()
   FileUtils.mv(sources_file, File.join(project_path, 'sources.json-backup'))
-  File.open(sources_file, 'w') {|f| f.puts(sources.to_json)}
-  `./prettyprint.py "#{sources_file}" "#{sources_file}"`
+  File.open(sources_file, 'w') {|f| f.puts(pretty_json.read)}
 end
 
 def project_path
diff --git a/prettyprint.py b/prettyprint.py
deleted file mode 100755
index c3ce629..0000000
--- a/prettyprint.py
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/usr/bin/env python
-
-"""
-Convert JSON data to human-readable form.
-
-Usage:
-  prettyJSON.py inputFile [outputFile]
-"""
-
-import sys
-import simplejson as json
-
-
-def main(args):
-    try:
-        inputFile = open(args[1])
-        input = json.load(inputFile)
-        inputFile.close()
-    except IndexError:
-        usage()
-        return False
-    if len(args) < 3:
-        print json.dumps(input, sort_keys = False, indent = 4)
-    else:
-        outputFile = open(args[2], "w")
-        json.dump(input, outputFile, sort_keys = False, indent = 4)
-        outputFile.close()
-    return True
-
-
-def usage():
-    print __doc__
-
-
-if __name__ == "__main__":
-    sys.exit(not main(sys.argv))