diff --git a/README.md b/README.md
index f502f41..f8ca72e 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ PlantUML mode for Emacs
 
 > “Pummel me all you want," I say. "Pummel me to death, in fact. My answers will not change."
 > The Invierno step back, frowning. "You must love her very much," he says, not unkindly.”
-> 
+>
 > from [The Bitter Kingdom - Fire and Thorns #3](https://www.goodreads.com/book/show/11431896-the-bitter-kingdom)
 
 
@@ -51,7 +51,7 @@ You can either tell `puml-mode` to autocomplete the word before the cursor by ty
 To render the PlantUML diagram within Emacs, you can also hit `M-x puml-preview`. This will run PlantUML and display the result in the `*PUML-Preview*` buffer. The format used to render the diagram is automagically chosen from what's supported by your Emacs. It will be one of the following, in order of preference:
 
 - SVG
-- ~~PNG~~ **still unsupported, see [#6](https://github.com/skuro/puml-mode/issues/6)**
+- PNG
 - Unicode ASCII art
 
 Default key bindings
diff --git a/puml-mode.el b/puml-mode.el
index 18efe91..55057c1 100644
--- a/puml-mode.el
+++ b/puml-mode.el
@@ -6,7 +6,7 @@
 ;; Author: Zhang Weize (zwz)
 ;; Maintainer: Carlo Sciolla (skuro)
 ;; Keywords: uml plantuml ascii
-;; Version: 0.5
+;; Version: 0.6
 
 ;; You can redistribute this program and/or modify it under the terms
 ;; of the GNU General Public License as published by the Free Software
@@ -120,8 +120,7 @@
 (defun puml-output-type ()
   "Detects the best output type to use for generated diagrams."
   (cond ((image-type-available-p 'svg) 'svg)
-        ; TODO: PNG is not yet supported, see issue #6
-        ((image-type-available-p 'png) 'utxt)
+        ((image-type-available-p 'png) 'png)
         ('utxt)))
 
 (defun puml-is-image-output-p ()
@@ -151,7 +150,9 @@
     (when b
       (kill-buffer b)))
   (let ((process-connection-type nil)
-        (buf (get-buffer-create puml-preview-buffer)))
+        (buf (get-buffer-create puml-preview-buffer))
+        (coding-system-for-read 'binary)
+        (coding-system-for-write 'binary))
     (let ((ps (start-process "PUML" buf
                              "java" "-jar" (shell-quote-argument puml-plantuml-jar-path)
                              (puml-output-type-opt) "-p")))