diff --git a/lxm3/xm_cluster/executable_specs.py b/lxm3/xm_cluster/executable_specs.py
index 5ac7d12..1397f87 100644
--- a/lxm3/xm_cluster/executable_specs.py
+++ b/lxm3/xm_cluster/executable_specs.py
@@ -54,6 +54,7 @@ class PythonPackage(job_blocks.ExecutableSpec):
     entrypoint: Union[CommandList, ModuleName]
     path: str = attr.ib(converter=utils.resolve_path_relative_to_launcher, default=".")
     resources: List[Fileset] = attr.ib(converter=list, default=attr.Factory(list))
+    extra_packages: List[str] = attr.ib(converter=list, default=attr.Factory(list))
 
     @property
     def name(self) -> str:
diff --git a/lxm3/xm_cluster/packaging/__init__.py b/lxm3/xm_cluster/packaging/__init__.py
index 4ad04a2..50beda3 100644
--- a/lxm3/xm_cluster/packaging/__init__.py
+++ b/lxm3/xm_cluster/packaging/__init__.py
@@ -55,6 +55,7 @@ def _create_archive(
                         "-t",
                         tmpdir,
                         package_dir,
+                        *py_package.extra_packages,
                     ],
                     text=True,
                     check=True,