diff --git a/hal/Usb.cpp b/hal/Usb.cpp
index 418f43c..ea45862 100644
--- a/hal/Usb.cpp
+++ b/hal/Usb.cpp
@@ -1099,7 +1099,7 @@
 
 static bool checkUsbInterfaceAutoSuspend(const std::string& devicePath,
         const std::string &intf) {
-  std::string bInterfaceClass;
+  std::string bInterfaceClass = "";
   int interfaceClass, ret = -1, retry = 3;
 
   do {