diff --git a/src/main/java/seatsio/events/Event.java b/src/main/java/seatsio/events/Event.java
index 7b9afca..509d354 100644
--- a/src/main/java/seatsio/events/Event.java
+++ b/src/main/java/seatsio/events/Event.java
@@ -34,6 +34,7 @@ public class Event extends ValueObject {
     public Map<String, CategoryKey> objectCategories;
     public List<Category> categories;
     public boolean isInThePast;
+    public List<String> partialSeasonKeysForEvent;
 
     public boolean isSeason() {
         return false;
diff --git a/src/test/java/seatsio/events/RetrieveEventTest.java b/src/test/java/seatsio/events/RetrieveEventTest.java
index 565ef5f..104d049 100644
--- a/src/test/java/seatsio/events/RetrieveEventTest.java
+++ b/src/test/java/seatsio/events/RetrieveEventTest.java
@@ -37,6 +37,7 @@ public void test() {
                 new Category(10L, "Cat2", "#5E42ED", false),
                 new Category("string11", "Cat3", "#5E42BB", false)
         );
+        assertThat(retrievedEvent.partialSeasonKeysForEvent).isNull();
     }
 
     @Test
@@ -70,5 +71,6 @@ public void retrieveSeason() {
                 new Category(10L, "Cat2", "#5E42ED", false),
                 new Category("string11", "Cat3", "#5E42BB", false)
         );
+        assertThat(retrievedSeason.partialSeasonKeysForEvent).isNull();
     }
 }
diff --git a/src/test/java/seatsio/seasons/AddEventsToPartialSeasonTest.java b/src/test/java/seatsio/seasons/AddEventsToPartialSeasonTest.java
index 5cc09c4..0119228 100644
--- a/src/test/java/seatsio/seasons/AddEventsToPartialSeasonTest.java
+++ b/src/test/java/seatsio/seasons/AddEventsToPartialSeasonTest.java
@@ -19,5 +19,6 @@ public void test() {
         assertThat(updatedPartialSeason.events)
                 .extracting(s -> s.key)
                 .containsExactly("event1", "event2");
+        assertThat(updatedPartialSeason.events.get(0).partialSeasonKeysForEvent).containsExactly("aPartialSeason");
     }
 }
diff --git a/src/test/java/seatsio/seasons/CreatePartialSeasonTest.java b/src/test/java/seatsio/seasons/CreatePartialSeasonTest.java
index 0b8d299..0ef1450 100644
--- a/src/test/java/seatsio/seasons/CreatePartialSeasonTest.java
+++ b/src/test/java/seatsio/seasons/CreatePartialSeasonTest.java
@@ -32,5 +32,6 @@ public void eventKeysCanBePassedIn() {
         Season season = client.seasons.createPartialSeason(topLevelSeason.key, null, newArrayList("event1", "event3"));
 
         assertThat(season.events).extracting(event -> event.key).containsExactly("event1", "event3");
+        assertThat(season.events.get(0).partialSeasonKeysForEvent).containsExactly(season.key);
     }
 }