diff --git a/rtl/accum/src/out_axis_fifo.sv b/rtl/accum/src/out_axis_fifo.sv
index 10d7faa..c73fa59 100644
--- a/rtl/accum/src/out_axis_fifo.sv
+++ b/rtl/accum/src/out_axis_fifo.sv
@@ -143,7 +143,7 @@ module out_axis_fifo #(
       .FIFO_WRITE_DEPTH(FIFO_WDEPTH), 
       .FULL_RESET_VALUE(0),
       .PROG_EMPTY_THRESH(PACKET_SIZE),
-      .PROG_FULL_THRESH(PACKET_SIZE),
+      .PROG_FULL_THRESH(PACKET_SIZE / (ACCUM_WIDTH / 8)),
       .RD_DATA_COUNT_WIDTH(RDEPTH_BITS),    
       .READ_DATA_WIDTH(8),           // always 8 bit for eth
       .READ_MODE("fwft"),