diff --git a/eg/demo.pl b/eg/demo.pl
index 1402765..8693ee7 100755
--- a/eg/demo.pl
+++ b/eg/demo.pl
@@ -171,9 +171,8 @@ package main;
 use Plack::Middleware::Static;
 $app = Plack::Middleware::Static->wrap($app, path => qr/^\/static/, root => dirname(__FILE__));
 
-# TODO should this be in Server
-use Plack::Middleware::Writer;
-$app = Plack::Middleware::Writer->wrap($app);
+use Tatsumaki::Middleware::Blocking;
+$app = Tatsumaki::Middleware::Blocking->wrap($app);
 
 # TODO this should be an external services module
 use Try::Tiny;
diff --git a/lib/Tatsumaki/Handler.pm b/lib/Tatsumaki/Handler.pm
index 68374a4..e8de2bd 100644
--- a/lib/Tatsumaki/Handler.pm
+++ b/lib/Tatsumaki/Handler.pm
@@ -85,11 +85,9 @@ sub run {
     }
 
     if ($self->is_asynchronous) {
-        unless ($self->request->env->{'psgi.streaming'}) {
-            Tatsumaki::Error::HTTP->throw(500, "asynchronous handlers need PSGI servers with psgi.streaming");
-        }
         my $cv = AE::cv;
         $self->condvar($cv);
+        $self->request->env->{'tatsumaki.block'} = sub { $cv->recv };
         return sub {
             my $start_response = shift;
             $cv->cb(sub {
@@ -97,10 +95,6 @@ sub run {
                 $self->writer($w) if $w;
             });
             $self->$method(@{$self->args});
-            unless ($self->request->env->{'psgi.nonblocking'}) {
-                $self->log("psgi.nonblocking is off: running " . ref($self) .  " in a blocking mode\n");
-                $cv->recv;
-            }
         };
     } else {
         $self->$method(@{$self->args});
diff --git a/lib/Tatsumaki/Middleware/Blocking.pm b/lib/Tatsumaki/Middleware/Blocking.pm
new file mode 100644
index 0000000..e73525a
--- /dev/null
+++ b/lib/Tatsumaki/Middleware/Blocking.pm
@@ -0,0 +1,30 @@
+package Tatsumaki::Middleware::Blocking;
+use strict;
+use base qw(Plack::Middleware);
+use Carp ();
+use Plack::Util;
+
+# Run asnynchronous Tatsumaki app in a blocking mode. See also Middleware::Writer
+sub call {
+    my($self, $env) = @_;
+
+    my $caller_supports_streaming = $env->{'psgi.streaming'};
+    $env->{'psgi.streaming'} = Plack::Util::TRUE;
+
+    my $res = $self->app->($env);
+    return $res if $caller_supports_streaming;
+
+    if (ref $res eq 'CODE') {
+        $env->{'psgi.errors'}->print("psgi.nonblocking is off: running $env->{PATH_INFO} in a blocking mode\n");
+        $res->(sub { $res = shift });
+        $env->{'tatsumaki.block'}->();
+    }
+
+    unless (defined $res->[2]) {
+        Carp::croak("stream_write is not supported on this server");
+    }
+
+    return $res;
+}
+
+1;