diff --git a/setup.cfg b/setup.cfg
index c88199716..fe205cd9b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -56,7 +56,7 @@ dev =
     selenium~=4.7.0
     webdriver-manager~=3.8
 optimade =
-    ipyoptimade~=0.2
+    ipyoptimade~=0.1
 smiles =
     rdkit>=2021.09.2
     scikit-learn~=1.0.0