diff --git a/src/Core/Varint.php b/src/Core/Varint.php
index cb94d22..e787cb7 100644
--- a/src/Core/Varint.php
+++ b/src/Core/Varint.php
@@ -10,6 +10,8 @@
 use Throwable;
 
 /**
+ * unsigned varint (VARiable INTeger).
+ *
  * @internal
  *
  * @link https://github.com/multiformats/unsigned-varint