diff --git a/var/spack/repos/builtin/packages/geant4/package.py b/var/spack/repos/builtin/packages/geant4/package.py
index 4cfcc4395e7..b559557340b 100644
--- a/var/spack/repos/builtin/packages/geant4/package.py
+++ b/var/spack/repos/builtin/packages/geant4/package.py
@@ -56,6 +56,7 @@ class Geant4(CMakePackage):
 
     # Python, with boost requirement dealt with in cxxstd section
     depends_on('python@3:', when='+python')
+    extends('python', when='+python')
     conflicts('+python', when='@:10.6.1',
               msg='Geant4 <= 10.6.1 cannont be built with Python bindings')