diff --git a/.github/workflows/moodle-ci.yml b/.github/workflows/moodle-ci.yml
index 9a07a9b65edf7e0cfee43290fc5fd7d49a48a195..53ca96f0d2be9beff215eef8bafd7b505338c20b 100644
--- a/.github/workflows/moodle-ci.yml
+++ b/.github/workflows/moodle-ci.yml
@@ -164,7 +164,7 @@ jobs:
         run: moodle-plugin-ci mustache
 
       - name: Grunt
-        if: ${{ always() }}
+        if: ${{ matrix.moodle-branch == 'MOODLE_401_STABLE' }}
         run: moodle-plugin-ci grunt
 
       - name: PHPUnit tests
diff --git a/doc/en/Plots/Plots.md b/doc/en/Plots/Plots.md
index 2f858ae1950e497b3890ac0411b44bbb583545a1..df117a94a175f73874de0f5349cbfaf6f8710e08 100644
--- a/doc/en/Plots/Plots.md
+++ b/doc/en/Plots/Plots.md
@@ -115,6 +115,13 @@ Now use:
 
     {@plot(pg2(x), [x,(x0-5),(x0+5)], [y,-10,10], [legend,false])@}
 
+A further example of a step functio:
+
+    step_fn(x,x0) := unit_step(x-x0-1/2) - unit_step(x-x0+1/2) + und*kron_delta(x,x0+1/2)+ und*kron_delta(x,x0-1/2);
+    p1:sum(step_fn(x,2*k),k,-3,3);
+
+which can be used with `{@plot(p1,[x,-5,5])@}`.
+
 For a discontinuous function, with end points, add in discrete plots.
 
     C:-5;