diff --git a/requirements.txt b/requirements.txt
index 5a078c0..bc5b957 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ scipy
 matplotlib
 ortools
 lark-parser
-pycddlib
+pycddlib < 3.0.0
 graphviz
 torch
 psitip == 1.1.6