diff --git a/bin/plantuml.jar b/bin/plantuml.jar
new file mode 100644
index 0000000..8c1eef7
Binary files /dev/null and b/bin/plantuml.jar differ
diff --git a/test/plantuml-mode-custom-jar-location-test.el b/test/plantuml-mode-custom-jar-location-test.el
new file mode 100644
index 0000000..d946a56
--- /dev/null
+++ b/test/plantuml-mode-custom-jar-location-test.el
@@ -0,0 +1,23 @@
+;;; plantuml-mode-custom-jar-location-test.el --- PlantUML Mode JAR location tests   -*- lexical-binding: t; -*-
+
+;; Author: Carlo Sciolla (skuro)
+;; Maintainer: Carlo Sciolla (skuro)
+;; URL: https://github.com/skuro/plantuml-mode
+
+;;; Commentary:
+
+;;; Code:
+
+(ert-deftest custom-jar-location ()
+  (setq-local plantuml-jar-path "~/.plantuml/plantuml.jar")
+  (should (equal `("-Djava.awt.headless=true" "-jar"
+                   ,(expand-file-name "~/.plantuml/plantuml.jar"))
+                 (plantuml-render-command)))
+
+  (setq-local plantuml-jar-path "/path/with spaces/plantuml.jar")
+  (should (equal `("-Djava.awt.headless=true" "-jar" "/path/with spaces/plantuml.jar")
+                 (plantuml-render-command))))
+
+(provide 'plantuml-mode-custom-jar-location-test)
+
+;;; plantuml-mode-custom-jar-location-test.el ends here
diff --git a/test/plantuml-mode-test.el b/test/plantuml-mode-test.el
index 81ba1bf..4c95184 100644
--- a/test/plantuml-mode-test.el
+++ b/test/plantuml-mode-test.el
@@ -12,4 +12,6 @@
   (should (equal (expand-file-name "~/plantuml.jar")
                  plantuml-jar-path)))
 
+(provide 'plantuml-mode-test)
+
 ;;; plantuml-mode-test.el ends here
diff --git a/test/plantuml-preview-test.el b/test/plantuml-preview-test.el
new file mode 100644
index 0000000..236b7a9
--- /dev/null
+++ b/test/plantuml-preview-test.el
@@ -0,0 +1,20 @@
+;;; plantuml-mode-preview-test.el --- PlantUML Mode preview tests   -*- lexical-binding: t; -*-
+
+;; Author: Carlo Sciolla (skuro)
+;; Maintainer: Carlo Sciolla (skuro)
+;; URL: https://github.com/skuro/plantuml-mode
+
+;;; Commentary:
+
+;;; Code:
+
+(ert-deftest preview-test ()
+  (setq-local plantuml-jar-path plantuml-test-jar-path)
+  (setq-local plantuml-output-type "utxt")
+  (plantuml-preview-string 42 (read-test-file "a-b.puml"))
+  (sleep-for 2)
+  (should (equal (read-test-file "a-b.txt") (read-preview-buffer))))
+
+(provide 'plantuml-mode-preview-test)
+
+;;; plantuml-mode-preview-test.el ends here
diff --git a/test/resources/a-b.puml b/test/resources/a-b.puml
new file mode 100644
index 0000000..8acbb1f
--- /dev/null
+++ b/test/resources/a-b.puml
@@ -0,0 +1,5 @@
+@startuml
+
+A -> B
+
+@enduml
diff --git a/test/resources/a-b.txt b/test/resources/a-b.txt
new file mode 100644
index 0000000..f4cd682
--- /dev/null
+++ b/test/resources/a-b.txt
@@ -0,0 +1,8 @@
+     ┌─┐          ┌─┐
+     │A│          │B│
+     └┬┘          └┬┘
+      │            │ 
+      │───────────>│ 
+     ┌┴┐          ┌┴┐
+     │A│          │B│
+     └─┘          └─┘
diff --git a/test/test-helper.el b/test/test-helper.el
index a52839a..6e9026c 100644
--- a/test/test-helper.el
+++ b/test/test-helper.el
@@ -16,6 +16,22 @@
 (defvar package-code-path
   (f-parent package-test-path))
 
+(defvar plantuml-test-resources-path
+  (f-join package-code-path "test/resources"))
+
+(defvar plantuml-test-jar-path
+  (f-join package-code-path "bin/plantuml.jar"))
+
+(defun read-buffer (bufname)
+  (with-current-buffer (get-buffer bufname)
+    (buffer-string)))
+
+(defun read-preview-buffer ()
+  (read-buffer plantuml-preview-buffer))
+
+(defun read-test-file (path)
+  (f-read (f-join plantuml-test-resources-path path) 'utf-8))
+
 (require 'plantuml-mode (f-expand "plantuml-mode.el" package-code-path))
 
 ;;; test-helper.el ends here