diff --git a/README.txt b/README.txt
index 5aab733..b83983e 100644
--- a/README.txt
+++ b/README.txt
@@ -12,7 +12,7 @@ Pixelflut (python)
 
 Gevent and pygame based python implementation. easier to hack with, but a bit slow. Not recommended for more than 20 players.
 
-    sudo aptitude install python-gevent python-pygame
+    sudo aptitude install python-gevent python-pygame python-cairo
     cd pixelflut
     mkdir save
     python pixelflut.py brain.py