diff --git a/target/linux/x86/base-files/etc/diag.sh b/target/linux/x86/base-files/etc/diag.sh
index 3af4b23583..d043e4f035 100644
--- a/target/linux/x86/base-files/etc/diag.sh
+++ b/target/linux/x86/base-files/etc/diag.sh
@@ -20,6 +20,8 @@ preinit_match_diag_led() {
 	json_init
 	json_load "$(cat $CFG)"
 	json_get_keys keys led
+	json_is_a led object || return
+
 	json_select led
 	for key in $keys; do
 		json_select "$key"