diff --git a/environment.yml b/environment.yml
index f3f2f71f8c844cc8b01483924f3cd43b067c13e1..8da2eaccecbc39866eafe345110b72b1aa814d44 100644
--- a/environment.yml
+++ b/environment.yml
@@ -8,4 +8,4 @@ dependencies:
   - pip:
     - scikit-learn
     - GPy
-    - Aalto-boss=1.5
+    - Aalto-boss==1.5