diff --git a/simpeg_drivers/components/factories/directives_factory.py b/simpeg_drivers/components/factories/directives_factory.py
index ba64bba1..ad5a7296 100644
--- a/simpeg_drivers/components/factories/directives_factory.py
+++ b/simpeg_drivers/components/factories/directives_factory.py
@@ -489,7 +489,10 @@ def assemble_keyword_arguments(
         name=None,
     ):
         receivers = inversion_object.entity
-        channels = getattr(receivers, "channels", [None])
+        channels = [
+            float(val) if val else None
+            for val in getattr(receivers, "channels", [None])
+        ]
         components = list(inversion_object.observed)
         ordering = inversion_object.survey.ordering
         n_locations = len(np.unique(ordering[:, 2]))
diff --git a/tests/run_tests/driver_mt_test.py b/tests/run_tests/driver_mt_test.py
index 059fa193..9bcc4a00 100644
--- a/tests/run_tests/driver_mt_test.py
+++ b/tests/run_tests/driver_mt_test.py
@@ -106,6 +106,10 @@ def test_magnetotellurics_fwr_run(
     )
     with get_workspace(tmp_path / "inversion_test.ui.geoh5") as geoh5:
         components = SyntheticsComponents(geoh5, options=opts)
+
+        # Test for label index supporting ints - bypass setter
+        components.survey.edit_em_metadata({"Channels": [10, 100, 1000]})
+
         params = MTForwardOptions.build(
             geoh5=geoh5,
             mesh=components.mesh,
@@ -127,6 +131,9 @@ def test_magnetotellurics_fwr_run(
     fwr_driver = MTForwardDriver(params)
     fwr_driver.run()
 
+    with Workspace(tmp_path / "inversion_test.ui.geoh5") as geoh5:
+        assert geoh5.get_entity("Iteration_0_zyy_real_[0]")[0] is not None
+
 
 def test_magnetotellurics_run(tmp_path: Path, max_iterations=1, pytest=True):
     # pass