diff --git a/projects/ipython.org/package.yml b/projects/ipython.org/package.yml
index 1c43ef50..6ed9b22b 100644
--- a/projects/ipython.org/package.yml
+++ b/projects/ipython.org/package.yml
@@ -11,6 +11,7 @@ provides:
 
 dependencies:
   python.org: '>=3.7<3.12'
+  gnu.org/which: 2 # used by the script
 
 build:
   script: |