diff --git a/systemdspawner/systemdspawner.py b/systemdspawner/systemdspawner.py
index d232471..1ce3b18 100644
--- a/systemdspawner/systemdspawner.py
+++ b/systemdspawner/systemdspawner.py
@@ -285,7 +285,7 @@ async def start(self):
 
         if self.extra_paths:
             new_path_list = [self._expand_user_vars(p) for p in self.extra_paths]
-            current_path = env.get("PATH")
+            current_path = env.get("PATH", os.defpath)
             if current_path:
                 new_path_list.append(current_path)
             env["PATH"] = ":".join(new_path_list)