diff --git a/ChangeLog b/ChangeLog
index fffaca14e8..166a300834 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri May  2 11:32:51 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* test/ruby/test_io.rb (test_seek, test_seek_symwhence): defer
+	  File::Statfs#type call which may not be implemented, to mitigate
+	  errors on platforms where SEEK_DATA is available but f_type in
+	  struct statfs is not.  [ruby-dev:48154] [Bug #9789]
+
 Fri May  2 10:37:55 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (rb_id_attrset): turn dynamically interned Symbol into
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index d2abd9e97d..5ed2ddd13b 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1715,7 +1715,7 @@ class TestIO < Test::Unit::TestCase
         open(t.path) { |f|
           break unless can_seek_data(f)
           assert_equal("foo\n", f.gets)
-          assert_nothing_raised("cannot SEEK_DATA on FS(0x%X)" % f.statfs.type) do
+          assert_nothing_raised(proc {"cannot SEEK_DATA on FS(0x%X)" % f.statfs.type}) do
             f.seek(0, IO::SEEK_DATA)
           end
           assert_equal("foo\nbar\nbaz\n", f.read)
@@ -1765,7 +1765,7 @@ class TestIO < Test::Unit::TestCase
         open(t.path) { |f|
           break unless can_seek_data(f)
           assert_equal("foo\n", f.gets)
-          assert_nothing_raised("cannot SEEK_DATA on FS(0x%X)" % f.statfs.type) do
+          assert_nothing_raised(proc {"cannot SEEK_DATA on FS(0x%X)" % f.statfs.type}) do
             f.seek(0, :DATA)
           end
           assert_equal("foo\nbar\nbaz\n", f.read)