diff --git a/nac3standalone/demo/check_demo.sh b/nac3standalone/demo/check_demo.sh
index d31ebe210..477fe1203 100755
--- a/nac3standalone/demo/check_demo.sh
+++ b/nac3standalone/demo/check_demo.sh
@@ -8,12 +8,15 @@ if [ -z "$1" ]; then
 fi
 
 declare -a nac3args
-while [ $# -ge 2 ]; do
+while [ $# -gt 1 ]; do
   case "$1" in
     --help)
-      echo "Usage: check_demo.sh [-i686] -- demo [NAC3ARGS...]"
+      echo "Usage: check_demo.sh [--debug] [-i686] -- [NAC3ARGS...] demo"
       exit
       ;;
+    --debug)
+      debug=1
+      ;;
     -i686)
       i686=1
       ;;
@@ -22,18 +25,18 @@ while [ $# -ge 2 ]; do
       break
       ;;
     *)
-      break
+      echo "Unrecognized argument \"$1\""
+      exit 1
       ;;
   esac
   shift
 done
 
-demo="$1"
-shift
 while [ $# -gt 1 ]; do
   nac3args+=("$1")
   shift
 done
+demo="$1"
 
 
 echo "### Checking $demo..."
@@ -43,12 +46,20 @@ echo ">>>>>> Running $demo with the Python interpreter"
 
 if [ -n "$i686" ]; then
   echo "...... Trying NAC3's 32-bit code generator output"
-  ./run_demo.sh -i686 --out run_32.log "${nac3args[@]}" "$demo"
+  if [ -n "$debug" ]; then
+    ./run_demo.sh --debug -i686 --out run_32.log -- "${nac3args[@]}" "$demo"
+  else
+    ./run_demo.sh -i686 --out run_32.log -- "${nac3args[@]}" "$demo"
+  fi
   diff -Nau interpreted.log run_32.log
 fi
 
 echo "...... Trying NAC3's 64-bit code generator output"
-./run_demo.sh --out run_64.log "${nac3args[@]}" "$demo"
+if [ -n "$debug" ]; then
+  ./run_demo.sh --debug --out run_64.log -- "${nac3args[@]}" "$demo"
+else
+  ./run_demo.sh --out run_64.log -- "${nac3args[@]}" "$demo"
+fi
 diff -Nau interpreted.log run_64.log
 
 echo "...... OK"
diff --git a/nac3standalone/demo/check_demos.sh b/nac3standalone/demo/check_demos.sh
index ae21142bf..2fa529234 100755
--- a/nac3standalone/demo/check_demos.sh
+++ b/nac3standalone/demo/check_demos.sh
@@ -2,6 +2,11 @@
 
 set -e
 
+if [ "$1" == "--help" ]; then
+    echo "Usage: check_demos.sh [CHECKARGS...] [--] [NAC3ARGS...]"
+    exit
+fi
+
 count=0
 for demo in src/*.py; do
   ./check_demo.sh "$@" "$demo"
diff --git a/nac3standalone/demo/run_demo.sh b/nac3standalone/demo/run_demo.sh
index 298024f5e..bec2eb6e7 100755
--- a/nac3standalone/demo/run_demo.sh
+++ b/nac3standalone/demo/run_demo.sh
@@ -14,7 +14,7 @@ declare -a nac3args
 while [ $# -ge 1 ]; do
   case "$1" in
     --help)
-      echo "Usage: run_demo.sh [--help] [--out OUTFILE] [--debug] [-i686] -- [NAC3ARGS...]"
+      echo "Usage: run_demo.sh [--help] [--out OUTFILE] [--debug] [-i686] -- [NAC3ARGS...] demo"
       exit
       ;;
     --out)
@@ -32,7 +32,8 @@ while [ $# -ge 1 ]; do
       break
       ;;
     *)
-      break
+      echo "Unrecognized argument \"$1\""
+      exit 1
       ;;
   esac
   shift
@@ -59,7 +60,7 @@ if [ -z "$i686" ]; then
   clang -c -std=gnu11 -Wall -Wextra -O3 -o demo.o demo.c
   clang -o demo module.o demo.o $DEMO_LINALG_STUB -lm -Wl,--no-warn-search-mismatch
 else
-  $nac3standalone --triple i686-unknown-linux-gnu "${nac3args[@]}"
+  $nac3standalone --triple i686-unknown-linux-gnu --target-features +sse2 "${nac3args[@]}"
   clang -m32 -c -std=gnu11 -Wall -Wextra -O3 -msse2 -o demo.o demo.c
   clang -m32 -o demo module.o demo.o $DEMO_LINALG_STUB32 -lm -Wl,--no-warn-search-mismatch
 fi