Index: uspace/lib/usb/src/request.c
===================================================================
--- uspace/lib/usb/src/request.c	(revision ad4562c21a6aaf832290f2af3b3d56a515bc3437)
+++ uspace/lib/usb/src/request.c	(revision 30db06c97ea02cfb2f8063707068ae167fc12f82)
@@ -504,5 +504,6 @@
  *
  * @param[in] pipe Control endpoint pipe (session must be already started).
- * @param[in] index String index (in native endianess).
+ * @param[in] index String index (in native endianess),
+ *	first index has number 1 (index from descriptors can be used directly).
  * @param[in] lang String language (in native endianess).
  * @param[out] string_ptr Where to store allocated string in native encoding.
@@ -515,6 +516,9 @@
 		return EBADMEM;
 	}
-	/* Index is actually one byte value. */
-	if (index > 0xFF) {
+	/*
+	 * Index is actually one byte value and zero index is used
+	 * to retrieve list of supported languages.
+	 */
+	if ((index < 1) || (index > 0xFF)) {
 		return ERANGE;
 	}