diff --git a/predicthq/endpoints/v1/events/schemas.py b/predicthq/endpoints/v1/events/schemas.py
index 0d4b5b4..19aa97e 100644
--- a/predicthq/endpoints/v1/events/schemas.py
+++ b/predicthq/endpoints/v1/events/schemas.py
@@ -112,7 +112,7 @@ class EventResultSet(ResultSet):
 
 class CountResultSet(BaseModel):
     count: int
-    top_rank: float
+    top_rank: Optional[float]
     rank_levels: dict
     categories: dict
     labels: dict
diff --git a/predicthq/version.py b/predicthq/version.py
index 88c513e..903a158 100644
--- a/predicthq/version.py
+++ b/predicthq/version.py
@@ -1 +1 @@
-__version__ = "3.3.0"
+__version__ = "3.4.0"