diff --git a/ChangeLog b/ChangeLog
index 3e73d3b08f..4c7f7e2a4c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Mar 10 09:49:54 2016  Rei Odaira  <Rei.Odaira@gmail.com>
+
+	* test/socket/test_socket.rb (test_udp_recvmsg_truncation):
+	  AIX does not set the MSG_TRUNC flag for a message partially read
+	  by recvmsg(2) with the MSG_PEEK flag set.
+
 Wed Mar  9 16:48:45 2016  Koichi Sasada  <ko1@atdot.net>
 
 	* benchmark/driver.rb: fix my last commit (syntax error).
diff --git a/test/socket/test_socket.rb b/test/socket/test_socket.rb
index a34d0e8b2a..7e75837e8f 100644
--- a/test/socket/test_socket.rb
+++ b/test/socket/test_socket.rb
@@ -709,7 +709,8 @@ class TestSocket < Test::Unit::TestCase
     s2.send("a" * 100, 0)
     ret, addr, rflags = s1.recvmsg(10, Socket::MSG_PEEK)
     assert_equal "a" * 10, ret
-    assert_equal Socket::MSG_TRUNC, rflags & Socket::MSG_TRUNC if !rflags.nil?
+    # AIX does not set MSG_TRUNC for a message partially read with MSG_PEEK.
+    assert_equal Socket::MSG_TRUNC, rflags & Socket::MSG_TRUNC if !rflags.nil? && /aix/ !~ RUBY_PLATFORM
     ret, addr, rflags = s1.recvmsg(10, 0)
     assert_equal "a" * 10, ret
     assert_equal Socket::MSG_TRUNC, rflags & Socket::MSG_TRUNC if !rflags.nil?