diff --git a/systemdspawner/systemdspawner.py b/systemdspawner/systemdspawner.py
index 9ad49d7..cc2850d 100644
--- a/systemdspawner/systemdspawner.py
+++ b/systemdspawner/systemdspawner.py
@@ -64,8 +64,6 @@ class SystemdSpawner(Spawner):
         """,
     ).tag(config=True)
 
-    # FIXME: Do not allow enabling this for systemd versions < 227,
-    # since that is when it was introduced.
     isolate_tmp = Bool(
         False,
         help="""