diff --git a/ChangeLog b/ChangeLog
index 8551aa2f00..3065786261 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jan  1 20:47:09 2009  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/socket.c (sock_s_getaddrinfo): use family_to_int.
+
 Thu Jan  1 20:17:47 2009  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/socket.c: include constants.h at top.
diff --git a/ext/socket/socket.c b/ext/socket/socket.c
index 6561c89b98..623a5a79fe 100644
--- a/ext/socket/socket.c
+++ b/ext/socket/socket.c
@@ -3252,14 +3252,10 @@ sock_s_getaddrinfo(int argc, VALUE *argv)
 	hints.ai_family = FIX2INT(family);
     }
     else if ((ap = StringValuePtr(family)) != 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 af;
+        if (family_to_int(ap, RSTRING_LEN(family), &af) == -1)
+	    rb_raise(rb_eSocket, "unknown socket domain %s", ap);
+        hints.ai_family = af;
     }
 
     if (!NIL_P(socktype)) {
diff --git a/test/socket/test_socket.rb b/test/socket/test_socket.rb
index 3133590ab1..15267c2623 100644
--- a/test/socket/test_socket.rb
+++ b/test/socket/test_socket.rb
@@ -110,4 +110,9 @@ class TestSocket < Test::Unit::TestCase
       assert_raise(ArgumentError) { Socket.unpack_sockaddr_un(addr) }
     }
   end
+
+  def test_getaddrinfo
+    # This should not send a DNS query because AF_UNIX.
+    assert_raise(SocketError) { Socket.getaddrinfo("www.kame.net", 80, "AF_UNIX") }
+  end
 end if defined?(Socket)