diff --git a/libraries/dsp/filter/tb/vhdl/tb_fil_ppf_wide.vhd b/libraries/dsp/filter/tb/vhdl/tb_fil_ppf_wide.vhd
index 65372c3e37e51333b5c21b68fadc9258388e52c6..5a78b3feec0bb25d7fccb3dcf633c3d5ae6058dd 100644
--- a/libraries/dsp/filter/tb/vhdl/tb_fil_ppf_wide.vhd
+++ b/libraries/dsp/filter/tb/vhdl/tb_fil_ppf_wide.vhd
@@ -110,7 +110,7 @@ architecture tb of tb_fil_ppf_wide is
   
   -- input/output data width
   constant c_in_dat_w            : natural := g_fil_ppf.in_dat_w;   
-  constant c_out_dat_w           : natural := g_fil_ppf.in_dat_w + g_fil_ppf.coef_dat_w + ceil_log2(g_fil_ppf.nof_taps);
+  constant c_out_dat_w           : natural := g_fil_ppf.out_dat_w;
 
   type t_wb_integer_arr2 is array(integer range <>) of t_integer_arr(c_nof_valid_in_filter-1 downto 0);