diff --git a/plantuml-mode.el b/plantuml-mode.el
index e90273d..a2747f4 100644
--- a/plantuml-mode.el
+++ b/plantuml-mode.el
@@ -222,7 +222,7 @@ default output type for new buffers."
                   plantuml-java-command
                   ,@plantuml-java-args
                   (expand-file-name plantuml-jar-path)
-                  (plantuml-output-type-opt) "-p"))
+                  (plantuml-output-type-opt) "-charset" "UTF-8" "-p"))
 
 (defun plantuml-preview-string (prefix string)
   "Preview diagram from PlantUML sources (as STRING), using prefix (as PREFIX)
diff --git a/test/resources/unicode.png b/test/resources/unicode.png
deleted file mode 100644
index cc6cb03..0000000
Binary files a/test/resources/unicode.png and /dev/null differ
diff --git a/test/resources/unicode.txt b/test/resources/unicode.txt
index bed17ca..f6c945e 100644
--- a/test/resources/unicode.txt
+++ b/test/resources/unicode.txt
@@ -1,8 +1,9 @@
-     ┌────┐          ┌──────┐
+     ┌────┐          ┌───┐
      │lang│          │日本語│
-     └──┬─┘          └───┬──┘
-        │                │ 
-        │────────-----──>│ 
-     ┌──┴─┐          ┌───┴──┐
+     └─┬──┘          └─┬─┘
+       │               │
+       │ ─────────────>│
+     ┌─┴──┐          ┌─┴─┐
      │lang│          │日本語│
-     └────┘          └──────┘
+     └────┘          └───┘
+