diff --git a/include/rtdbg.h b/include/rtdbg.h
index c0a4e682221e05a5fc036caf5585883081b360be..6a6ea3d670fbaab5028fd7b52038dbe6f7b62b11 100644
--- a/include/rtdbg.h
+++ b/include/rtdbg.h
@@ -178,6 +178,8 @@ extern "C" {
 
 #define LOG_RAW(...)         dbg_raw(__VA_ARGS__)
 
+#define LOG_HEX(name, width, buf, size)
+
 #endif /* defined(RT_USING_ULOG) && define(DBG_ENABLE) */
 
 #ifdef __cplusplus