diff --git a/build/start-container.sh b/build/start-container.sh
index e60fb2a..2ea4966 100644
--- a/build/start-container.sh
+++ b/build/start-container.sh
@@ -6,10 +6,12 @@ set -e
 # install extra packages and extensions on first boot
 if [[ ! -f /etc/first_boot ]]; then
     if [[ -n "${EXTRA_APK_PACKAGES// /}" ]]; then
-        apk add --no-cache "$EXTRA_APK_PACKAGES"
+        # shellcheck disable=SC2086
+        apk add --no-cache $EXTRA_APK_PACKAGES
     fi
     if [[ -n "${EXTRA_PHP_EXTENSIONS// /}" ]]; then
-        docker-php-ext-install "$EXTRA_PHP_EXTENSIONS"
+        # shellcheck disable=SC2086
+        docker-php-ext-install $EXTRA_PHP_EXTENSIONS
     fi
     touch /etc/first_boot
 fi