diff --git a/plugins/cpu/cpu-usage-by-process b/plugins/cpu/cpu-usage-by-process
index ae6469a6..74a0d6ef 100755
--- a/plugins/cpu/cpu-usage-by-process
+++ b/plugins/cpu/cpu-usage-by-process
@@ -29,7 +29,7 @@ if [ "$1" = "autoconf" ] ; then
     if [ -n "$procs" ] ; then
         echo "yes"
     else
-        echo "\$procs not defined."
+        echo "no (environment variable 'procs' is not defined)"
     fi
     exit
 fi