diff --git a/src/tools/codelines b/src/tools/codelines
index b74a0c792e..c72cab442f 100755
--- a/src/tools/codelines
+++ b/src/tools/codelines
@@ -1,4 +1,5 @@
 :
 
 # This script is used to compute the total number of "C" lines in the release
+# This should be run from the top of the CVS tree after a 'make distclean'
 find . -name '*.[chyl]' | xargs cat| wc -l