diff --git a/hydroflow_lang/src/graph/ops/_lattice_join_fused_join.rs b/hydroflow_lang/src/graph/ops/_lattice_join_fused_join.rs
index ca0e5ed108f4..121e955a9927 100644
--- a/hydroflow_lang/src/graph/ops/_lattice_join_fused_join.rs
+++ b/hydroflow_lang/src/graph/ops/_lattice_join_fused_join.rs
@@ -88,7 +88,7 @@ pub const _LATTICE_JOIN_FUSED_JOIN: OperatorConstraints = OperatorConstraints {
     is_external_input: false,
     ports_inn: Some(|| super::PortListSpec::Fixed(parse_quote! { 0, 1 })),
     ports_out: None,
-    input_delaytype_fn: |_| Some(DelayType::Stratum),
+    input_delaytype_fn: |_| Some(DelayType::MonotoneAccum),
     input_edgetype_fn: |_| Some(GraphEdgeType::Value),
     output_edgetype_fn: |_| GraphEdgeType::Value,
     flow_prop_fn: None,