diff --git a/include/usb-dbg.hpp b/include/usb-dbg.hpp
index 0f6a0c7..e5102c4 100644
--- a/include/usb-dbg.hpp
+++ b/include/usb-dbg.hpp
@@ -124,7 +124,7 @@
 {
     uint8_t parent;
     uint8_t item_num;
-    char item_str[8][32];
+    std::string item_str[8];
     uint8_t (*select)(uint8_t item);
 };