diff --git a/v1.0/UserGuide.yml b/v1.0/UserGuide.yml
index 4ec35504d..60c32863a 100644
--- a/v1.0/UserGuide.yml
+++ b/v1.0/UserGuide.yml
@@ -661,8 +661,11 @@
     - $include: examples/expression.cwl
     - |
       ```
+      
+      As this tool does not require any `inputs` we can run it with an empty job file:
 
       ```
+      $ touch empty.yml
       $ cwl-runner expression.cwl empty.yml
       [job 140000594593168] /home/example$ echo -A 2 -B baz -C 10 9 8 7 6 5 4 3 2 1
       -A 2 -B baz -C 10 9 8 7 6 5 4 3 2 1