diff --git a/lib/libusb/libusb.h b/lib/libusb/libusb.h
--- a/lib/libusb/libusb.h
+++ b/lib/libusb/libusb.h
@@ -210,6 +210,8 @@
 	LIBUSB_ERROR_OTHER = -99,
 };
 
+#define LIBUSB_ERROR_COUNT 14
+
 enum libusb_speed {
 	LIBUSB_SPEED_UNKNOWN = 0,
 	LIBUSB_SPEED_LOW = 1,
@@ -482,7 +484,8 @@
 int	libusb_init(libusb_context ** context);
 int	libusb_init_context(libusb_context **, const struct libusb_init_option [], int num_options);
 void	libusb_exit(struct libusb_context *ctx);
-int	libusb_has_capability(uint32_t capability);
+int libusb_has_capability(uint32_t capability);
+int libusb_setlocale(const char *locale);
 
 /* Device handling and enumeration */
 
diff --git a/lib/libusb/libusb10.h b/lib/libusb/libusb10.h
--- a/lib/libusb/libusb10.h
+++ b/lib/libusb/libusb10.h
@@ -150,6 +150,12 @@
 	struct libusb20_device *os_priv;
 };
 
+struct libusb_language_context {
+	const char *lang_name;
+	const char
+	    *err_strs[LIBUSB_ERROR_COUNT + 1]; /* All error Plus 1 UNKNOWN */
+};
+
 extern struct libusb_context *usbi_default_context;
 
 void	libusb10_add_pollfd(libusb_context *ctx, struct libusb_super_pollfd *pollfd, struct libusb20_device *pdev, int fd, short events);
diff --git a/lib/libusb/libusb10.c b/lib/libusb/libusb10.c
--- a/lib/libusb/libusb10.c
+++ b/lib/libusb/libusb10.c
@@ -29,6 +29,8 @@
 #ifdef LIBUSB_GLOBAL_INCLUDE_FILE
 #include LIBUSB_GLOBAL_INCLUDE_FILE
 #else
+
+#include <ctype.h>
 #include <assert.h>
 #include <errno.h>
 #include <poll.h>
@@ -81,6 +83,48 @@
 	.describe = "https://www.freebsd.org"
 };
 
+static const struct libusb_language_context libusb_language_ctx[] = {
+	{
+	    .lang_name = "en",
+	    .err_strs = { "Success", "I/O error", 
+			"Invalid parameter",
+			"Permissions error",
+			"No device",
+			"Not found",
+			"Device busy",
+			"Timeout",
+			"Overflow",
+			"Pipe error",
+			"Interrupted",
+			"Out of memory",
+			"Not supported",
+			"Other error",
+			"Unknown error",
+		}
+	},
+	{	
+		.lang_name = "zh",
+		.err_strs = { "成功", "I/O 錯誤",
+			"不合法的參數",
+			"權限錯誤",
+			"找不到設備",
+			"找不到",
+			"設備忙碌中",
+			"超時",
+			"溢位",
+			"管線錯誤",
+			"被中斷",
+			"記憶體不足",
+			"不支援",
+			"其他錯誤",
+			"未知錯誤",
+		}
+	},
+};
+
+static const struct libusb_language_context *default_language_context =
+    &libusb_language_ctx[0];
+
 const struct libusb_version *
 libusb_get_version(void)
 {
@@ -1696,38 +1740,20 @@
 const char *
 libusb_strerror(int code)
 {
-	switch (code) {
-	case LIBUSB_SUCCESS:
-		return ("Success");
-	case LIBUSB_ERROR_IO:
-		return ("I/O error");
-	case LIBUSB_ERROR_INVALID_PARAM:
-		return ("Invalid parameter");
-	case LIBUSB_ERROR_ACCESS:
-		return ("Permissions error");
-	case LIBUSB_ERROR_NO_DEVICE:
-		return ("No device");
-	case LIBUSB_ERROR_NOT_FOUND:
-		return ("Not found");
-	case LIBUSB_ERROR_BUSY:
-		return ("Device busy");
-	case LIBUSB_ERROR_TIMEOUT:
-		return ("Timeout");
-	case LIBUSB_ERROR_OVERFLOW:
-		return ("Overflow");
-	case LIBUSB_ERROR_PIPE:
-		return ("Pipe error");
-	case LIBUSB_ERROR_INTERRUPTED:
-		return ("Interrupted");
-	case LIBUSB_ERROR_NO_MEM:
-		return ("Out of memory");
-	case LIBUSB_ERROR_NOT_SUPPORTED:
-		return ("Not supported");
-	case LIBUSB_ERROR_OTHER:
-		return ("Other error");
-	default:
-		return ("Unknown error");
-	}
+	int entry = -code;
+
+	/*
+	 * The libusb upstream consider all code out of range a
+	 * LIBUSB_ERROR_OTHER. In FreeBSD, it is a special unknown error. We
+	 * preserve the FreeBSD implementation as I think it make sense.
+	 */
+	if (entry < 0 || entry >= LIBUSB_ERROR_COUNT)
+		return (default_language_context->err_strs[LIBUSB_ERROR_COUNT]);
+
+	if (code == LIBUSB_ERROR_OTHER)
+		entry = 13;
+
+	return default_language_context->err_strs[entry];
 }
 
 const char *
@@ -1781,3 +1807,30 @@
 		return (0);
 	}
 }
+
+int
+libusb_setlocale(const char *locale)
+{
+	int idx;
+	const char *lang;
+	const int nitems = sizeof(libusb_language_ctx) /
+	    sizeof(*libusb_language_ctx);
+
+	if (locale == NULL || strlen(locale) < 2 ||
+	    (locale[2] != '\0' && (*strchr("-_.", locale[2]) == 0)))
+		return (LIBUSB_ERROR_INVALID_PARAM);
+
+	for (idx = 0; idx < nitems; ++idx) {
+		lang = libusb_language_ctx[idx].lang_name;
+		if (tolower(locale[0]) == lang[0] &&
+		    tolower(locale[1]) == lang[1])
+			break;
+	}
+
+	if (idx == nitems)
+		return (LIBUSB_ERROR_INVALID_PARAM);
+
+	default_language_context = &libusb_language_ctx[idx];
+
+	return (LIBUSB_SUCCESS);
+}