diff --git a/binder/environment.yml b/binder/environment.yml
index d71d65633..573a6160a 100644
--- a/binder/environment.yml
+++ b/binder/environment.yml
@@ -2,7 +2,7 @@ channels:
   - defaults
   - r
 dependencies:
-  - python=3
+  - python=3.9
   - numpy
   - scipy
   - pandas