diff --git a/nac3standalone/demo/check_demo.sh b/nac3standalone/demo/check_demo.sh
new file mode 100755
index 0000000..5ea8e18
--- /dev/null
+++ b/nac3standalone/demo/check_demo.sh
@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+set -e
+
+if [ -z "$1" ]; then
+  echo "Requires at least one argument"
+  exit 1
+fi
+
+demo="${@:-1}"
+set -- "${@:1:$(($# - 1))}"
+
+echo -n "Checking $demo... "
+./interpret_demo.py "$demo" > interpreted.log
+./run_demo.sh "$@" "$demo" > run.log
+diff -Nau interpreted.log run.log
+echo "ok"
diff --git a/nac3standalone/demo/check_demos.sh b/nac3standalone/demo/check_demos.sh
index d7fa8b1..ae21142 100755
--- a/nac3standalone/demo/check_demos.sh
+++ b/nac3standalone/demo/check_demos.sh
@@ -4,12 +4,8 @@ set -e
 
 count=0
 for demo in src/*.py; do
-    echo -n "checking $demo... "
-    ./interpret_demo.py $demo > interpreted.log
-    ./run_demo.sh "$@" $demo > run.log
-    diff -Nau interpreted.log run.log
-    echo "ok"
-    let "count+=1"
+  ./check_demo.sh "$@" "$demo"
+  ((count += 1))
 done
 
 echo "Ran $count demo checks - PASSED"