diff --git a/scripts/build.sh b/scripts/build.sh
index eaf2a8f..8e0774d 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -281,7 +281,7 @@ fi
 
 require_su() {
     if test "$(whoami)" != "root"; then
-        if [ -z "$SUDO" ] && [ "$($SUDO whoami)" != "root" ]; then
+        if [ -z "$SUDO" ] || [ "$($SUDO whoami)" != "root" ]; then
             echo "ROOT/SUDO is required to run this script"
             abort
         fi
diff --git a/scripts/run.sh b/scripts/run.sh
index e2777b3..3c1c2f8 100755
--- a/scripts/run.sh
+++ b/scripts/run.sh
@@ -120,7 +120,7 @@ winetricks list-installed | grep -E "^msxml6" >/dev/null 2>&1 || {
 }
 WHIPTAIL=$(command -v whiptail 2>/dev/null)
 DIALOG=$(command -v dialog 2>/dev/null)
-DIALOG=${WHIPTAIL:DIALOG}
+DIALOG=${WHIPTAIL:-$DIALOG}
 function Radiolist {
     declare -A o="$1"
     shift