diff --git a/machinarium/makefile b/machinarium/makefile
index 43a74734..9adf8f9a 100644
--- a/machinarium/makefile
+++ b/machinarium/makefile
@@ -12,7 +12,8 @@ OBJECTS = mm_context.o \
           mm_ioconnect.o \
           mm_iobind.o \
           mm_ioaccept.o \
-          mm_ioread.o
+          mm_ioread.o \
+          mm_iowrite.o
 LIB     = libmachinarium.a
 $(LIB): clean $(OBJECTS)
 	$(AR) cr $(LIB) $(OBJECTS)
diff --git a/machinarium/mm_iowrite.c b/machinarium/mm_iowrite.c
new file mode 100644
index 00000000..02f87c19
--- /dev/null
+++ b/machinarium/mm_iowrite.c
@@ -0,0 +1,78 @@
+
+/*
+ * machinarium.
+ *
+ * Cooperative multitasking engine.
+*/
+
+#include <machinarium_private.h>
+#include <machinarium.h>
+
+static void
+mm_io_write_timeout_cb(uv_timer_t *handle)
+{
+	mmio *io = handle->data;
+	io->write_timeout = 1;
+	mm_io_close_handle(io, (uv_handle_t*)&io->write);
+}
+
+static void
+mm_io_write_cb(uv_write_t *handle, int status)
+{
+	mmio *io = handle->data;
+	if (mm_fiber_is_cancel(io->write_fiber))
+		goto wakeup;
+	if (io->write_timeout)
+		goto wakeup;
+	mm_io_timer_stop(io, &io->write_timer);
+wakeup:
+	io->write_status = status;
+	mm_wakeup(io->f, io->write_fiber);
+}
+
+static void
+mm_io_write_cancel_cb(mmfiber *fiber, void *arg)
+{
+	mmio *io = arg;
+	io->write_timeout = 0;
+	mm_io_timer_stop(io, &io->write_timer);
+	mm_io_close_handle(io, (uv_handle_t*)&io->write);
+}
+
+MM_API int
+mm_write(mmio_t iop, char *buf, int size, uint64_t time_ms)
+{
+	mmio *io = iop;
+	mmfiber *current = mm_current(io->f);
+	if (mm_fiber_is_cancel(current))
+		return -ECANCELED;
+	if (!io->connected || io->write_fiber)
+		return -1;
+	io->write_status  = 0;
+	io->write_timeout = 0;
+	io->write_fiber   = current;
+
+	mm_io_timer_start(io, &io->connect_timer, mm_io_write_timeout_cb,
+	                  time_ms);
+	int rc;
+	uv_buf_t req = { buf, size };
+	rc = uv_write(&io->write, (uv_stream_t*)&io->handle,
+	              &req, 1, mm_io_write_cb);
+	if (rc < 0) {
+		io->write_fiber = NULL;
+		return rc;
+	}
+	mm_fiber_op_begin(io->write_fiber, mm_io_write_cancel_cb, io);
+	mm_scheduler_yield(&io->f->scheduler);
+	mm_fiber_op_end(io->write_fiber);
+	rc = io->write_status;
+	io->write_fiber = NULL;
+	return rc;
+}
+
+MM_API int
+mm_write_is_timeout(mmio_t iop)
+{
+	mmio *io = iop;
+	return io->write_timeout;
+}