diff --git a/requirements.txt b/requirements.txt
index aad2c8cd1f5aadba909da6fa41ed5bded87b3433..c74af83a8cebab7ae2026642c011a408ccb4fec1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,3 +21,4 @@ bob.learn.boosting
 bob.ip.facedetect
 bob.ip.flandmark
 matplotlib   # for plotting
+gridtk