diff --git a/gns3server/utils/asyncio/__init__.py b/gns3server/utils/asyncio/__init__.py
index d459cb18..efc32d06 100644
--- a/gns3server/utils/asyncio/__init__.py
+++ b/gns3server/utils/asyncio/__init__.py
@@ -71,10 +71,10 @@ async def subprocess_check_output(*args, cwd=None, env=None, stderr=False):
 
     if stderr:
         proc = await asyncio.create_subprocess_exec(*args, stderr=asyncio.subprocess.PIPE, cwd=cwd, env=env)
-        output = await proc.stderr.read()
+        _, output = await proc.communicate()
     else:
         proc = await asyncio.create_subprocess_exec(*args, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.DEVNULL, cwd=cwd, env=env)
-        output = await proc.stdout.read()
+        output, _ = await proc.communicate()
     if output is None:
         return ""
     # If we received garbage we ignore invalid characters
diff --git a/tests/compute/iou/test_iou_vm.py b/tests/compute/iou/test_iou_vm.py
index 93fbb78d..19a8ba70 100644
--- a/tests/compute/iou/test_iou_vm.py
+++ b/tests/compute/iou/test_iou_vm.py
@@ -102,6 +102,7 @@ async def test_start(vm):
 
     with asyncio_patch("asyncio.create_subprocess_exec", return_value=mock_process) as mock_exec:
         mock_process.returncode = None
+        mock_process.communicate = AsyncioMagicMock(return_value=(None, None))
         await vm.start()
         assert vm.is_running()
         assert vm.command_line == ' '.join(mock_exec.call_args[0])
@@ -130,6 +131,7 @@ async def test_start_with_iourc(vm, tmpdir):
     with patch("gns3server.config.Config.get_section_config", return_value={"iourc_path": fake_file}):
         with asyncio_patch("asyncio.create_subprocess_exec", return_value=mock_process) as exec_mock:
             mock_process.returncode = None
+            mock_process.communicate = AsyncioMagicMock(return_value=(None, None))
             await vm.start()
             assert vm.is_running()
             arsgs, kwargs = exec_mock.call_args
@@ -165,11 +167,12 @@ async def test_stop(vm):
     future = asyncio.Future()
     future.set_result(True)
     process.wait.return_value = future
+    process.returncode = None
+    process.communicate = AsyncioMagicMock(return_value=(None, None))
 
     with asyncio_patch("asyncio.create_subprocess_exec", return_value=process):
         with asyncio_patch("gns3server.utils.asyncio.wait_for_process_termination"):
             await vm.start()
-            process.returncode = None
             assert vm.is_running()
             await vm.stop()
             assert vm.is_running() is False
@@ -190,6 +193,7 @@ async def test_reload(vm, fake_iou_bin):
     future.set_result(True)
     process.wait.return_value = future
     process.returncode = None
+    process.communicate = AsyncioMagicMock(return_value=(None, None))
 
     with asyncio_patch("asyncio.create_subprocess_exec", return_value=process):
         with asyncio_patch("gns3server.utils.asyncio.wait_for_process_termination"):
@@ -202,10 +206,13 @@ async def test_reload(vm, fake_iou_bin):
 
 async def test_close(vm, port_manager):
 
+    process = MagicMock()
+    process.returncode = None
+    process.communicate = AsyncioMagicMock(return_value=(None, None))
     vm._start_ubridge = AsyncioMagicMock(return_value=True)
     vm._ubridge_send = AsyncioMagicMock()
     with asyncio_patch("gns3server.compute.iou.iou_vm.IOUVM._check_requirements", return_value=True):
-        with asyncio_patch("asyncio.create_subprocess_exec", return_value=MagicMock()):
+        with asyncio_patch("asyncio.create_subprocess_exec", return_value=process):
             await vm.start()
             port = vm.console
             await vm.close()