diff --git a/_kosmorro/i18n/strings.py b/_kosmorro/i18n/strings.py
index 10be55c..0da2f5c 100644
--- a/_kosmorro/i18n/strings.py
+++ b/_kosmorro/i18n/strings.py
@@ -1,26 +1,20 @@
 #!/usr/bin/env python3
 
+from typing import Union
 from .utils import _
 
 from kosmorrolib import EventType, MoonPhaseType, ObjectIdentifier, Event
 
 
-def from_event(event: Event, with_description: bool = True) -> str:
+def from_event(event: Event, with_description: bool = True) -> Union[None, str]:
     string, details = {
         EventType.OPPOSITION: (_("%s is in opposition"), None),
         EventType.CONJUNCTION: (_("%s and %s are in conjunction"), None),
         EventType.OCCULTATION: (_("%s occults %s"), None),
-        EventType.MAXIMAL_ELONGATION: (
-            _("Elongation of %s is maximal"),
-            (
-                "{:.3n}°".format(event.details["deg"])
-                if type(event.details) is dict
-                else event.details
-            ),
-        ),
+        EventType.MAXIMAL_ELONGATION: (_("Elongation of %s is maximal"), lambda e: "{:.3n}°".format(e.details["deg"])),
         EventType.PERIGEE: (_("%s is at its perigee"), None),
         EventType.APOGEE: (_("%s is at its apogee"), None),
-    }.get(event.event_type)
+    }.get(event.event_type, (None, None))
 
     if string is None:
         return None
@@ -28,7 +22,7 @@ def from_event(event: Event, with_description: bool = True) -> str:
     string = string % tuple([from_object(o.identifier) for o in event.objects])
 
     if details is not None and with_description:
-        return "%s (%s)" % (string, details)
+        return "%s (%s)" % (string, details())
 
     return string