diff --git a/crates/polars-pipe/src/executors/sinks/sort/sink.rs b/crates/polars-pipe/src/executors/sinks/sort/sink.rs
index 0f66db59b5a3..1411a76c872d 100644
--- a/crates/polars-pipe/src/executors/sinks/sort/sink.rs
+++ b/crates/polars-pipe/src/executors/sinks/sort/sink.rs
@@ -146,6 +146,9 @@ impl Sink for SortSink {
 
     fn combine(&mut self, other: &mut dyn Sink) {
         let other = other.as_any().downcast_mut::<Self>().unwrap();
+        if let Some(ooc_start) = other.ooc_start {
+            self.ooc_start = Some(ooc_start);
+        }
         self.chunks.extend(std::mem::take(&mut other.chunks));
         self.ooc |= other.ooc;
         self.dist_sample