diff --git a/ext/socket/ifaddr.c b/ext/socket/ifaddr.c
index 4e2fc065c0..3c9548110e 100644
--- a/ext/socket/ifaddr.c
+++ b/ext/socket/ifaddr.c
@@ -262,7 +262,7 @@ ifaddr_dstaddr(VALUE self)
  *   ifaddr.vhid => Integer
  *
  * Returns the vhid address of _ifaddr_.
- * nil is returned if there is no vhid
+ * nil is returned if there is no vhid.
  */
 
 static VALUE