diff --git a/README.md b/README.md
index 953f346..878c77c 100644
--- a/README.md
+++ b/README.md
@@ -9,9 +9,11 @@
 Requirements
 ------------
 You need to install the [Shanghai][1] font on your system. To do that, download the `zip`-file provided on the upper link, extract the `shanghai.ttf` and install it on your system (on most systems this can be done by double click and the file and click the install button).
+Additionally you need a `json` [library][2]
 
 Future plans
 ------------
 For the future a network based client is planned.
 
 [1]:http://www.dafont.com/de/shanghai.font
+[2]:http://mvnrepository.com/artifact/org.json/json