diff --git a/drivers/usb/gadget/g_dnl.c b/drivers/usb/gadget/g_dnl.c
index 0491a0eea941902bb6cf494dccb9e8f64d6eae20..039331a5afd9cadc2b9306da9af848b218e397d6 100644
--- a/drivers/usb/gadget/g_dnl.c
+++ b/drivers/usb/gadget/g_dnl.c
@@ -19,6 +19,8 @@
 #include <dfu.h>
 #include <thor.h>
 
+#include <env_callback.h>
+
 #include "gadget_chips.h"
 #include "composite.c"
 
@@ -202,6 +204,19 @@ static int g_dnl_get_bcd_device_number(struct usb_composite_dev *cdev)
 	return g_dnl_get_board_bcd_device_number(gcnum);
 }
 
+/**
+ * Update internal serial number variable when the "serial#" env var changes.
+ *
+ * Handle all cases, even when flags == H_PROGRAMMATIC or op == env_op_delete.
+ */
+static int on_serialno(const char *name, const char *value, enum env_op op,
+		int flags)
+{
+	g_dnl_set_serialnumber((char *)value);
+	return 0;
+}
+U_BOOT_ENV_CALLBACK(serialno, on_serialno);
+
 static int g_dnl_bind(struct usb_composite_dev *cdev)
 {
 	struct usb_gadget *gadget = cdev->gadget;
diff --git a/include/env_callback.h b/include/env_callback.h
index 90b95b5e6676087f00d234721c98c7e475cf4268..5c4a30c2deeed2fd810f6f7fbb6c7dfdd2aacde0 100644
--- a/include/env_callback.h
+++ b/include/env_callback.h
@@ -72,6 +72,7 @@
 	SILENT_CALLBACK \
 	SPLASHIMAGE_CALLBACK \
 	"stdin:console,stdout:console,stderr:console," \
+	"serial#:serialno," \
 	CONFIG_ENV_CALLBACK_LIST_STATIC
 
 struct env_clbk_tbl {