diff --git a/config.sh b/config.sh
index 9c5cd7e..3436876 100755
--- a/config.sh
+++ b/config.sh
@@ -100,5 +100,6 @@ touch /.autorelabel
 #======================================
 mkdir -p /boot/efi/m1n1
 update-m1n1 /boot/efi/m1n1/boot.bin
+rm /boot/.builder
 
 exit 0
diff --git a/post_bootstrap.sh b/post_bootstrap.sh
new file mode 100755
index 0000000..91ad0d5
--- /dev/null
+++ b/post_bootstrap.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# Flag file to ensure update-m1n1 doesn't try to autodetect the ESP
+touch /boot/.builder
+
+exit 0