diff --git a/ChangeLog b/ChangeLog
index 7d03094923..e2585b84d1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jan  1 21:26:05 2009  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/socket.c (sock_s_getnameinfo): use family_to_int.
+
 Thu Jan  1 21:08:34 2009  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/mkconstants.rb: check all alias possibility. 
diff --git a/ext/socket/socket.c b/ext/socket/socket.c
index 623a5a79fe..04b79ff3c3 100644
--- a/ext/socket/socket.c
+++ b/ext/socket/socket.c
@@ -3369,14 +3369,10 @@ sock_s_getnameinfo(int argc, VALUE *argv)
 	    hints.ai_family = FIX2INT(af);
 	}
 	else if ((ap = StringValuePtr(af)) != 0) {
-	    if (strcmp(ap, "AF_INET") == 0) {
-		hints.ai_family = PF_INET;
-	    }
-#ifdef INET6
-	    else if (strcmp(ap, "AF_INET6") == 0) {
-		hints.ai_family = PF_INET6;
-	    }
-#endif
+            int family;
+            if (family_to_int(ap, RSTRING_LEN(af), &family) == -1)
+                rb_raise(rb_eSocket, "unknown socket domain %s", ap);
+            hints.ai_family = family;
 	}
 	error = getaddrinfo(hptr, pptr, &hints, &res);
 	if (error) goto error_exit_addr;
diff --git a/test/socket/test_socket.rb b/test/socket/test_socket.rb
index 15267c2623..4c88177c9e 100644
--- a/test/socket/test_socket.rb
+++ b/test/socket/test_socket.rb
@@ -115,4 +115,8 @@ class TestSocket < Test::Unit::TestCase
     # This should not send a DNS query because AF_UNIX.
     assert_raise(SocketError) { Socket.getaddrinfo("www.kame.net", 80, "AF_UNIX") }
   end
+
+  def test_getnameinfo
+    assert_raise(SocketError) { Socket.getnameinfo(["AF_UNIX", 80, "0.0.0.0"]) }
+  end
 end if defined?(Socket)