diff --git a/crates/core/src/planner/streaming_window.rs b/crates/core/src/planner/streaming_window.rs
index 9d9996a..9a5239e 100644
--- a/crates/core/src/planner/streaming_window.rs
+++ b/crates/core/src/planner/streaming_window.rs
@@ -128,7 +128,7 @@ impl ExtensionPlanner for StreamingWindowPlanner {
                 };
 
                 let initial_aggr = Arc::new(FranzStreamingWindowExec::try_new(
-                    AggregateMode::Partial,
+                    AggregateMode::Single,
                     groups.clone(),
                     aggregates.clone(),
                     filters.clone(),