diff --git a/rpi23-gen-image.sh b/rpi23-gen-image.sh
index 93a05f1..8e14ece 100755
--- a/rpi23-gen-image.sh
+++ b/rpi23-gen-image.sh
@@ -473,7 +473,8 @@ if [ -n "$MISSING_PACKAGES" ] ; then
   [ "$confirm" != "y" ] && exit 1
 
   # Make sure all missing required packages are installed
-  apt-get -qq -y install "$(echo "${MISSING_PACKAGES}" | sed "s/ //")"
+  apt-get update
+  apt-get -qq -y install "$MISSING_PACKAGES"
 fi
 
 # Check if ./bootstrap.d directory exists