diff --git a/python/swiftest/tests/bin2xr/swiftest/bin2xr_swiftest.py b/python/swiftest/tests/bin2xr/swiftest/bin2xr_swiftest.py
index 4437247be..9a377876a 100644
--- a/python/swiftest/tests/bin2xr/swiftest/bin2xr_swiftest.py
+++ b/python/swiftest/tests/bin2xr/swiftest/bin2xr_swiftest.py
@@ -1,5 +1,5 @@
 import swiftest
 import swiftest.io as swio
 param_file = "param.swiftest.in"
-sim = swiftest.Simulation(source="param.swiftest.in")
+sim = swiftest.Simulation(param_file="param.swiftest.in")
 ds = swio.swiftest2xr(sim.param)
\ No newline at end of file