diff --git a/rtl/accum/src/accum_top.sv b/rtl/accum/src/accum_top.sv
index 359ce15..dc788a1 100644
--- a/rtl/accum/src/accum_top.sv
+++ b/rtl/accum/src/accum_top.sv
@@ -66,6 +66,7 @@ module accumulator_top
 
             if (start_accept) begin
                 calc_active     <= 1'b1;
+                window_size_reg <= window_size_safe;
             end else if (finish_pulse) begin
                 calc_active <= 1'b0;
             end