diff --git a/pkg/transformers/seqgen.go b/pkg/transformers/seqgen.go
index 06e6f3d11..b7a5b0f58 100644
--- a/pkg/transformers/seqgen.go
+++ b/pkg/transformers/seqgen.go
@@ -183,6 +183,11 @@ func (tr *TransformerSeqgen) Transform(
 	inputDownstreamDoneChannel <-chan bool,
 	outputDownstreamDoneChannel chan<- bool,
 ) {
+	if !inrecAndContext.EndOfStream {
+		// Discard upstream records; generate output only when upstream is done.
+		return
+	}
+
 	counter := tr.start
 	context := types.NewNilContext()
 	context.UpdateForStartOfFile("seqgen")