diff --git a/gateware/boards/colorlight_i5/sysmgr.v b/gateware/boards/colorlight_i5/sysmgr.v
index fd194ba..40418ba 100644
--- a/gateware/boards/colorlight_i5/sysmgr.v
+++ b/gateware/boards/colorlight_i5/sysmgr.v
@@ -5,7 +5,6 @@ module sysmgr (
 	input  wire clk_in,
 	input  wire rst_in,
 	output wire clk_256fs,
-	output wire clk_fs,
 	output wire rst_out
 );
 
@@ -15,12 +14,10 @@ wire pll_reset;
 wire rst_i;
 
 reg [7:0] rst_cnt;
-reg [7:0] clkdiv;
 
 assign pll_reset = rst_in;
 assign rst_i = ~rst_cnt[7];
 assign rst_out = rst_i;
-assign clk_fs = clkdiv[7];
 
 `ifndef VERILATOR_LINT_ONLY
 
@@ -75,10 +72,4 @@ always @(posedge clk_in)
     else if (~rst_cnt[7])
         rst_cnt <= rst_cnt + 1;
 
-always @(posedge clk_256fs)
-    if (rst_i)
-        clkdiv <= 8'h00;
-    else
-        clkdiv <= clkdiv + 1;
-
 endmodule // sysmgr
diff --git a/gateware/boards/ecpix5/sysmgr.v b/gateware/boards/ecpix5/sysmgr.v
index c9c3340..02954ef 100644
--- a/gateware/boards/ecpix5/sysmgr.v
+++ b/gateware/boards/ecpix5/sysmgr.v
@@ -5,7 +5,6 @@ module sysmgr (
 	input  wire clk_in,
 	input  wire rst_in,
 	output wire clk_256fs,
-	output wire clk_fs,
 	output wire rst_out
 );
 
@@ -15,12 +14,10 @@ wire pll_reset;
 wire rst_i;
 
 reg [7:0] rst_cnt;
-reg [7:0] clkdiv;
 
 assign rst_i = ~rst_cnt[7];
 assign rst_out = rst_i;
 assign pll_reset = rst_in;
-assign clk_fs = clkdiv[7];
 
 `ifndef VERILATOR_LINT_ONLY
 
@@ -71,10 +68,4 @@ always @(posedge clk_in)
     else if (~rst_cnt[7])
         rst_cnt <= rst_cnt + 1;
 
-always @(posedge clk_256fs)
-    if (rst_i)
-        clkdiv <= 8'h00;
-    else
-        clkdiv <= clkdiv + 1;
-
 endmodule // sysmgr
diff --git a/gateware/boards/gatemate_evb/sysmgr.v b/gateware/boards/gatemate_evb/sysmgr.v
index 1117e04..7615e0e 100644
--- a/gateware/boards/gatemate_evb/sysmgr.v
+++ b/gateware/boards/gatemate_evb/sysmgr.v
@@ -4,7 +4,6 @@ module sysmgr (
 	input  wire clk_in,
 	input  wire rst_in,
 	output wire clk_256fs,
-	output wire clk_fs,
 	output wire rst_out
 );
 
@@ -14,12 +13,10 @@ wire pll_reset;
 wire rst_i;
 
 reg [7:0] rst_cnt;
-reg [7:0] clkdiv;
 
 assign pll_reset = rst_in;
 assign rst_i = ~rst_cnt[7];
 assign rst_out = rst_i;
-assign clk_fs = clkdiv[7];
 
 `ifndef VERILATOR_LINT_ONLY
 
@@ -46,10 +43,4 @@ always @(posedge clk_in)
     else if (~rst_cnt[7])
         rst_cnt <= rst_cnt + 1;
 
-always @(posedge clk_256fs)
-    if (rst_i)
-        clkdiv <= 8'h00;
-    else
-        clkdiv <= clkdiv + 1;
-
 endmodule // sysmgr
diff --git a/gateware/boards/pico_ice/sysmgr.v b/gateware/boards/pico_ice/sysmgr.v
index 83cbeed..09a6b57 100644
--- a/gateware/boards/pico_ice/sysmgr.v
+++ b/gateware/boards/pico_ice/sysmgr.v
@@ -3,7 +3,6 @@
 module sysmgr (
 	input  wire rst_in,
 	output wire clk_256fs,
-	output wire clk_fs,
 	output wire rst_out
 );
 
@@ -11,10 +10,8 @@ module sysmgr (
 	wire rst_i;
 
 	reg [7:0] rst_cnt = 8'h80;
-    reg [7:0] clkdiv;
 
     assign clk_256fs = clk_12m;
-    assign clk_fs = clkdiv[7];
 	assign rst_i = rst_cnt[7];
 
 `ifndef VERILATOR_LINT_ONLY
@@ -35,12 +32,6 @@ module sysmgr (
 		else if (rst_cnt[7])
 			rst_cnt <= rst_cnt + 1;
 
-    always @(posedge clk_256fs)
-        if (rst_i)
-            clkdiv <= 8'h00;
-        else
-            clkdiv <= clkdiv + 1;
-
 `ifndef VERILATOR_LINT_ONLY
 	SB_GB rst_gbuf_I (
 		.USER_SIGNAL_TO_GLOBAL_BUFFER(rst_i),
diff --git a/gateware/cores/digital_echo.sv b/gateware/cores/digital_echo.sv
index ad1e217..80d650d 100644
--- a/gateware/cores/digital_echo.sv
+++ b/gateware/cores/digital_echo.sv
@@ -10,7 +10,7 @@
 module digital_echo #(
     parameter W = 16,
     // Length of the echo buffers in samples.
-    parameter ECHO_LEN = 4096,
+    parameter ECHO_LEN = 4096
 )(
     input rst,
     input clk,
diff --git a/gateware/scripts/verilator_lint.sh b/gateware/scripts/verilator_lint.sh
index 2c63734..5416ee1 100755
--- a/gateware/scripts/verilator_lint.sh
+++ b/gateware/scripts/verilator_lint.sh
@@ -56,6 +56,6 @@ verilator --lint-only cores/util/filter/karlsen_lpf.sv
 verilator --lint-only cores/util/filter/karlsen_lpf_pipelined.sv
 verilator --lint-only -Icores -Icores/util/filter filter.sv
 verilator --lint-only -Icores -Icores/util pitch_shift.sv
-verilator --lint-only -Icores -Icores/util stereo_echo.sv
+verilator --lint-only -Icores -Icores/util digital_echo.sv
 verilator --lint-only -Icores -Icores/util dc_block.sv
 verilator --lint-only -Icores -Icores/util wavetable_osc.sv