diff --git a/bacnet-stack/comment.sh b/bacnet-stack/comment.sh
index 84ee554e..edce137b 100755
--- a/bacnet-stack/comment.sh
+++ b/bacnet-stack/comment.sh
@@ -1,16 +1,22 @@
 #!/bin/sh
+# This script converts any C++ comments to C comments
+# using the ccmtcnvt tool from the liwc package
+
+# silent fail if the tool is not installed
+[ -x /usr/bin/ccmtcnvt ] || exit 0
+
 directory=${1-`pwd`}
 for filename in $( find $directory -name '*.c' )
 do
   echo Converting $filename
-  ccmtcnvt $filename > /tmp/ccmtcnvt.karg
+  /usr/bin/ccmtcnvt $filename > /tmp/ccmtcnvt.karg
   mv /tmp/ccmtcnvt.karg $filename
 done
 
 for filename in $( find $directory -name '*.h' )
 do
   echo Converting $filename
-  ccmtcnvt $filename > /tmp/ccmtcnvt.karg
+  /usr/bin/ccmtcnvt $filename > /tmp/ccmtcnvt.karg
   mv /tmp/ccmtcnvt.karg $filename
 done