diff --git a/plugins/UM3NetworkPrinting/src/SendMaterialJob.py b/plugins/UM3NetworkPrinting/src/SendMaterialJob.py
index 697ba33a6b..0186783f1f 100644
--- a/plugins/UM3NetworkPrinting/src/SendMaterialJob.py
+++ b/plugins/UM3NetworkPrinting/src/SendMaterialJob.py
@@ -126,7 +126,7 @@ class SendMaterialJob(Job):
                                                         .format(file_name = signature_file_name), f.read()))
 
         Logger.log("d", "Syncing material {material_id} with cluster.".format(material_id = material_id))
-        self.device.postFormWithParts(target = "materials/", parts = parts, on_finished = self.sendingFinished)
+        self.device.postFormWithParts(target = "/materials/", parts = parts, on_finished = self.sendingFinished)
 
     ##  Check a reply from an upload to the printer and log an error when the call failed
     @staticmethod
diff --git a/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py b/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py
index 75be120ac5..61323861b6 100644
--- a/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py
+++ b/plugins/UM3NetworkPrinting/tests/TestSendMaterialJob.py
@@ -210,7 +210,7 @@ class TestSendMaterialJob(TestCase):
         self.assertEqual(1, device_mock.postFormWithParts.call_count)
         self.assertEqual(
             [call.createFormPart("name=\"file\"; filename=\"generic_pla_white.xml.fdm_material\"", "<xml></xml>"),
-             call.postFormWithParts(target = "materials/", parts = ["_xXx_"], on_finished = job.sendingFinished)],
+             call.postFormWithParts(target = "/materials/", parts = ["_xXx_"], on_finished = job.sendingFinished)],
             device_mock.method_calls)
 
     @patch("UM.Application.Application.getInstance")
@@ -240,5 +240,5 @@ class TestSendMaterialJob(TestCase):
         self.assertEqual(1, device_mock.postFormWithParts.call_count)
         self.assertEqual(
             [call.createFormPart("name=\"file\"; filename=\"generic_pla_white.xml.fdm_material\"", "<xml></xml>"),
-             call.postFormWithParts(target = "materials/", parts = ["_xXx_"], on_finished = job.sendingFinished)],
+             call.postFormWithParts(target = "/materials/", parts = ["_xXx_"], on_finished = job.sendingFinished)],
             device_mock.method_calls)