diff --git a/swash/processing/swash.py b/swash/processing/swash.py
index 1fb78df..fa30723 100644
--- a/swash/processing/swash.py
+++ b/swash/processing/swash.py
@@ -43,7 +43,7 @@ with tempfile.TemporaryDirectory(prefix="swash_", dir=".") as tmp_raw:
     with open(tmpdir.joinpath("sws.log"), "w") as logfile:
         log.info(f"Runing swash in '{tmpdir}'")
 
-        cmd = (config.get("swash", "swashrun"), "-input", inp.name, *mpi)
+        cmd = (config.get("swash", "swashrun"), *mpi, "-input", inp.name)
         log.info(f"Running {cmd}")
 
         swash_run = subprocess.Popen(