diff --git a/build b/build
index 4259753..add0aea 100755
--- a/build
+++ b/build
@@ -137,7 +137,7 @@ BR2_ROOTFS_POST_SCRIPT_ARGS=\"${post_script_args}\"
   fi
   if [ -n "$linux_kernel_custom_config_file" ]; then
     if [ -f "$linux_kernel_custom_config_file" ]; then
-      printf "BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE=\"${linux_kernel_custom_config_file}\"\n" >> "$config_file"
+      printf "BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y\nBR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE=\"${linux_kernel_custom_config_file}\"\n" >> "$config_file"
       if "${linux_reconfigure}"; then
         touch "${linux_kernel_custom_config_file}"
       fi