4 files changed, 14 insertions, 2 deletions
diff --git a/test/io/nonblock/test_flush.rb b/test/io/nonblock/test_flush.rb
index 63e16db5a3..08d129de3f 100644
--- a/test/io/nonblock/test_flush.rb
+++ b/test/io/nonblock/test_flush.rb
@@ -53,6 +53,7 @@ class TestIONonblock < Test::Unit::TestCase
 
   def test_nonblock
     IO.pipe {|r, w|
+      w.nonblock = false
       assert_equal(false, w.nonblock?)
       w.nonblock do
         assert_equal(true, w.nonblock?)
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 1960166393..9d0e5bc411 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1360,6 +1360,7 @@ class TestIO < Test::Unit::TestCase
   def test_readpartial_lock
     with_pipe do |r, w|
       s = ""
+      r.nonblock = false if have_nonblock?
       t = Thread.new { r.readpartial(5, s) }
       Thread.pass until t.stop?
       assert_raise(RuntimeError) { s.clear }
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index 16eb3e4e76..4c212c13f2 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -770,6 +770,15 @@ class TestProcess < Test::Unit::TestCase
           Process.wait pid
         end
       }
+
+      # ensure standard FDs we redirect to are blocking for compatibility
+      with_pipes(3) do |pipes|
+        src = 'p [STDIN,STDOUT,STDERR].map(&:nonblock?)'
+        rdr = { 0 => pipes[0][0], 1 => pipes[1][1], 2 => pipes[2][1] }
+        pid = spawn(RUBY, '-rio/nonblock', '-e', src, rdr)
+        assert_equal("[false, false, false]\n", pipes[1][0].gets)
+        Process.wait pid
+      end
     end
   end
 
diff --git a/test/socket/test_basicsocket.rb b/test/socket/test_basicsocket.rb
index d388b4f0dd..71d8fd66c1 100644
--- a/test/socket/test_basicsocket.rb
+++ b/test/socket/test_basicsocket.rb
@@ -159,8 +159,9 @@ class TestSocket_BasicSocket < Test::Unit::TestCase
       set_nb = true
       buf = String.new
       if ssock.respond_to?(:nonblock?)
-        assert_not_predicate(ssock, :nonblock?)
-        assert_not_predicate(csock, :nonblock?)
+        assert_predicate(ssock, :nonblock?)
+        assert_predicate(csock, :nonblock?)
+        csock.nonblock = ssock.nonblock = false
 
         # Linux may use MSG_DONTWAIT to avoid setting O_NONBLOCK
         if RUBY_PLATFORM.match?(/linux/) && Socket.const_defined?(:MSG_DONTWAIT)