diff --git a/vsrc/SimDTM.v b/vsrc/SimDTM.v
index a5f8c233..293e7841 100644
--- a/vsrc/SimDTM.v
+++ b/vsrc/SimDTM.v
@@ -1,4 +1,5 @@
 // See LICENSE.SiFive for license details.
+//VCS coverage exclude_file
 
 import "DPI-C" function int debug_tick
 (
diff --git a/vsrc/SimJTAG.v b/vsrc/SimJTAG.v
index fbc19d9e..385af3c2 100644
--- a/vsrc/SimJTAG.v
+++ b/vsrc/SimJTAG.v
@@ -1,5 +1,5 @@
 // See LICENSE.SiFive for license details.
-
+//VCS coverage exclude_file
 import "DPI-C" function int jtag_tick
 (
  output bit jtag_TCK,
diff --git a/vsrc/TestDriver.v b/vsrc/TestDriver.v
index 0984f151..2948d43a 100644
--- a/vsrc/TestDriver.v
+++ b/vsrc/TestDriver.v
@@ -1,5 +1,5 @@
 // See LICENSE.SiFive for license details.
-
+//VCS coverage exclude_file
 `ifndef RESET_DELAY
  `define RESET_DELAY 777.7
 `endif
diff --git a/vsrc/jtag_vpi.v b/vsrc/jtag_vpi.v
index 45d426b1..ab618093 100644
--- a/vsrc/jtag_vpi.v
+++ b/vsrc/jtag_vpi.v
@@ -31,7 +31,7 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
-
+//VCS coverage exclude_file
 `define CMD_RESET		0
 `define CMD_TMS_SEQ		1
 `define CMD_SCAN_CHAIN		2
diff --git a/vsrc/plusarg_reader.v b/vsrc/plusarg_reader.v
index 0d245f9e..a8425291 100644
--- a/vsrc/plusarg_reader.v
+++ b/vsrc/plusarg_reader.v
@@ -1,5 +1,7 @@
 // See LICENSE.SiFive for license details.
 
+//VCS coverage exclude_file
+
 // No default parameter values are intended, nor does IEEE 1800-2012 require them (clause A.2.4 param_assignment),
 // but Incisive demands them. These default values should never be used.
 module plusarg_reader #(parameter FORMAT="borked=%d", DEFAULT=0) (