diff --git a/libraries/dsp/st/src/vhdl/mmp_st_histogram.vhd b/libraries/dsp/st/src/vhdl/mmp_st_histogram.vhd
index 68f9df5f48febfe34b87ffd864ebcbef7b8e85b6..f3b8d63dd9d07e43421c52ac82a05f86ba464ec4 100644
--- a/libraries/dsp/st/src/vhdl/mmp_st_histogram.vhd
+++ b/libraries/dsp/st/src/vhdl/mmp_st_histogram.vhd
@@ -67,7 +67,7 @@ ARCHITECTURE str OF mmp_st_histogram IS
   -------------------------------------------------------------------------------
   CONSTANT c_reg_adr_w : NATURAL := 1;
   CONSTANT c_ram_adr_w : NATURAL := ceil_log2(g_nof_bins);
-  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync)+1;
+  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync+1);
 
   CONSTANT c_ram                    : t_c_mem := (latency  => 1,
                                                   adr_w    => c_ram_adr_w, 
diff --git a/libraries/dsp/st/src/vhdl/st_histogram.vhd b/libraries/dsp/st/src/vhdl/st_histogram.vhd
index 297aa95ccaa5345645b2af153518e42cc34e85e8..5bc18db0f52cc561810ef66653252aba3fdda085 100644
--- a/libraries/dsp/st/src/vhdl/st_histogram.vhd
+++ b/libraries/dsp/st/src/vhdl/st_histogram.vhd
@@ -126,7 +126,7 @@ ARCHITECTURE rtl OF st_histogram IS
   -------------------------------------------------------------------------------
   CONSTANT c_ram_adr_w : NATURAL := ceil_log2(g_nof_bins);
   CONSTANT c_adr_low   : NATURAL := g_data_w-c_ram_adr_w; 
-  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync)+1;
+  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync+1);
 
   -------------------------------------------------------------------------------
   -- snk_in.data help signal
diff --git a/libraries/dsp/st/tb/vhdl/tb_mmp_st_histogram.vhd b/libraries/dsp/st/tb/vhdl/tb_mmp_st_histogram.vhd
index 0880f312c4ddd540f741ddc297fb7b4387621be2..e2e34b149bcf1a1d3fe32bcdd06df094f788dfa4 100644
--- a/libraries/dsp/st/tb/vhdl/tb_mmp_st_histogram.vhd
+++ b/libraries/dsp/st/tb/vhdl/tb_mmp_st_histogram.vhd
@@ -90,7 +90,7 @@ ARCHITECTURE tb OF tb_mmp_st_histogram IS
   ----------------------------------------------------------------------------
   -- Readout & verification
   ----------------------------------------------------------------------------
-  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync)+1;
+  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync+1);
 
   CONSTANT c_expected_ram_content : NATURAL := g_nof_data_per_sync/g_nof_bins;
 
diff --git a/libraries/dsp/st/tb/vhdl/tb_st_histogram.vhd b/libraries/dsp/st/tb/vhdl/tb_st_histogram.vhd
index e5701611d8027c34ad59bf59d424a200227b3415..b4410b98bb0e7b94437fe353058676095a124b83 100644
--- a/libraries/dsp/st/tb/vhdl/tb_st_histogram.vhd
+++ b/libraries/dsp/st/tb/vhdl/tb_st_histogram.vhd
@@ -84,7 +84,7 @@ ARCHITECTURE tb OF tb_st_histogram IS
   ---------------------------------------------------------------------------
   CONSTANT c_expected_ram_content_counter : NATURAL := g_nof_data_per_sync/g_nof_bins;
   CONSTANT c_nof_levels_per_bin           : NATURAL := (2**g_data_w)/g_nof_bins; --e.g. 2 values per bin if g_data_w=9 (512 levels) and g_nof_bins=256
-  CONSTANT c_ram_dat_w                    : NATURAL := ceil_log2(g_nof_data_per_sync)+1;
+  CONSTANT c_ram_dat_w                    : NATURAL := ceil_log2(g_nof_data_per_sync+1);
   CONSTANT c_ram_adr_w                    : NATURAL := ceil_log2(g_nof_bins);
     
   ---------------------------------------------------------------------------