diff --git a/tests/device_tests/test_msg_signtx.py b/tests/device_tests/test_msg_signtx.py
index c70b88e32d..54f550df8f 100644
--- a/tests/device_tests/test_msg_signtx.py
+++ b/tests/device_tests/test_msg_signtx.py
@@ -370,6 +370,8 @@ class TestMsgSigntx:
 
     @pytest.mark.setup_client(mnemonic=MNEMONIC12)
     @pytest.mark.skip_ui
+    @pytest.mark.slow
+    @pytest.mark.timeout(600)
     def test_lots_of_inputs(self, client):
         # Tests if device implements serialization of len(inputs) correctly
         # tx 4a7b7e0403ae5607e473949cfa03f09f2cd8b0f404bf99ce10b7303d86280bf7 : 100 UTXO for spending for unit tests
@@ -399,6 +401,8 @@ class TestMsgSigntx:
 
     @pytest.mark.setup_client(mnemonic=MNEMONIC12)
     @pytest.mark.skip_ui
+    @pytest.mark.slow
+    @pytest.mark.timeout(600)
     def test_lots_of_outputs(self, client):
         # Tests if device implements serialization of len(outputs) correctly