diff --git a/raspi-config b/raspi-config
index 3120aac..1175c4f 100755
--- a/raspi-config
+++ b/raspi-config
@@ -166,7 +166,7 @@ do_memory_split() {
     [ -z "$CUR_GPU_MEM" ] && CUR_GPU_MEM=64
     ## ask users what gpu_mem they want
     NEW_GPU_MEM=$(whiptail --inputbox "How much memory should the GPU have?  e.g. 16/32/64/128/256" \
-      20 70 "$CUR_GPU_MEM" 3>&1 1>&2 2>&3)
+      20 70 -- "$CUR_GPU_MEM" 3>&1 1>&2 2>&3)
     if [ $? -eq 0 ]; then
       set_config_var gpu_mem "$NEW_GPU_MEM" /boot/config.txt
       ASK_TO_REBOOT=1