diff --git a/src/urh/ui/SimulatorScene.py b/src/urh/ui/SimulatorScene.py
index cb8ec8ed0a..13740dd476 100644
--- a/src/urh/ui/SimulatorScene.py
+++ b/src/urh/ui/SimulatorScene.py
@@ -347,6 +347,15 @@ def dropEvent(self, event: QDropEvent):
         nodes_to_add.extend([file_node for file_node in file_nodes if file_node not in nodes_to_add])
         protocols_to_add = [node.protocol for node in nodes_to_add]
 
+
+        self.add_protocols(protocols_to_add)
+
+        self.update_view()
+
+        super().dropEvent(event)
+
+
+    def add_protocols(self, protocols_to_add: list):
         for protocol in protocols_to_add:
             for message in protocol.messages:
                 source, destination = self.__detect_source_destination(message)
@@ -356,10 +365,6 @@ def dropEvent(self, event: QDropEvent):
                 self.items.append(simulator_message)
                 self.addItem(simulator_message)
 
-        self.update_view()
-
-        super().dropEvent(event)
-
     def __detect_source_destination(self, message: Message):
         # TODO: use SRC_ADDRESS and DST_ADDRESS labels
         participants = self.controller.project_manager.participants
diff --git a/tests/test_simulator.py b/tests/test_simulator.py
new file mode 100644
index 0000000000..d116acdc86
--- /dev/null
+++ b/tests/test_simulator.py
@@ -0,0 +1,27 @@
+import unittest
+import tests.utils_testing
+from urh import constants
+from urh.controller.MainController import MainController
+
+from tests.utils_testing import get_path_for_data_file
+
+app = tests.utils_testing.app
+
+
+class TestSimulator(unittest.TestCase):
+    def setUp(self):
+        self.old_sym_len = constants.SETTINGS.value('rel_symbol_length', type=int)
+        constants.SETTINGS.setValue('rel_symbol_length', 0)  # Disable Symbols for this Test
+
+        self.form = MainController()
+        self.form.add_signalfile(get_path_for_data_file("esaver.complex"))
+        self.sframe = self.form.signal_tab_controller.signal_frames[0]
+        self.sim_frame = self.form.simulator_tab_controller
+        self.form.ui.tabWidget.setCurrentIndex(3)
+
+    def tearDown(self):
+        constants.SETTINGS.setValue('rel_symbol_length', self.old_sym_len) # Restore Symbol Length
+
+    def test_add_signal(self):
+        self.sim_frame.ui.gvSimulator.scene().add_protocols([self.sframe.proto_analyzer])
+        self.assertEqual(len(self.sim_frame.ui.gvSimulator.scene().items), len(self.sframe.proto_analyzer.messages))