diff --git a/posthog/hogql/printer.py b/posthog/hogql/printer.py
index 1f7e5339deee1..77f2a0661aa77 100644
--- a/posthog/hogql/printer.py
+++ b/posthog/hogql/printer.py
@@ -1250,6 +1250,8 @@ def _is_nullable(self, node: ast.Expr) -> bool:
             return node.value is None
         elif isinstance(node.type, ast.PropertyType):
             return True
+        elif isinstance(node.type, ast.CallType):
+            return node.type.return_type.nullable
         elif isinstance(node.type, ast.FieldType):
             return node.type.is_nullable(self.context)
         elif isinstance(node, ast.Alias):