diff --git a/var/spack/repos/builtin/packages/edm4hep/package.py b/var/spack/repos/builtin/packages/edm4hep/package.py
index e108ca3d19..1c4cb76b3e 100644
--- a/var/spack/repos/builtin/packages/edm4hep/package.py
+++ b/var/spack/repos/builtin/packages/edm4hep/package.py
@@ -124,6 +124,9 @@ def cmake_args(self):
         args.append(self.define("BUILD_TESTING", self.run_tests))
         return args
 
+    def setup_run_environment(self, env):
+        env.prepend_path("PYTHONPATH", self.prefix.python)
+
     def url_for_version(self, version):
         """Translate version numbers to ilcsoft conventions.
         in spack, the convention is: 0.1 (or 0.1.0) 0.1.1, 0.2, 0.2.1 ...