diff --git a/lib_xua/api/xua_conf_default.h b/lib_xua/api/xua_conf_default.h
index 79aa061b..a1fc3514 100644
--- a/lib_xua/api/xua_conf_default.h
+++ b/lib_xua/api/xua_conf_default.h
@@ -442,6 +442,16 @@
 #define CODEC_MASTER       (0)
 #endif
 
+/**
+ * @brief Serial Number String used by the device
+ *
+ * Default: ""
+ */
+#ifndef SERIAL_STR
+#define SERIAL_STR               ""
+#endif
+
+
 /**
  * @brief Vendor String used by the device. This is also pre-pended to various strings used by the design.
  *
diff --git a/lib_xua/src/core/endpoint0/xua_endpoint0.c b/lib_xua/src/core/endpoint0/xua_endpoint0.c
index e91d61fc..384aee2a 100755
--- a/lib_xua/src/core/endpoint0/xua_endpoint0.c
+++ b/lib_xua/src/core/endpoint0/xua_endpoint0.c
@@ -118,7 +118,8 @@ char g_product_str[XUA_MAX_STR_LEN] = PRODUCT_STR_A2;
 char g_product_str[XUA_MAX_STR_LEN] = PRODUCT_STR_A1;
 #endif
 
-char g_serial_str[XUA_MAX_STR_LEN] = "";
+/* Global variable for current USB Serial Number strings */
+char g_serial_str[XUA_MAX_STR_LEN] = SERIAL_STR;
 
 /* Subslot */
 const unsigned g_subSlot_Out_HS[OUTPUT_FORMAT_COUNT]    = {HS_STREAM_FORMAT_OUTPUT_1_SUBSLOT_BYTES,