diff --git a/stimela/cargo/cab/pycasacore/src/run.py b/stimela/cargo/cab/pycasacore/src/run.py
index 65f466fb..e075bcec 100644
--- a/stimela/cargo/cab/pycasacore/src/run.py
+++ b/stimela/cargo/cab/pycasacore/src/run.py
@@ -34,7 +34,7 @@
     tfile.write(custom_script)
     tfile.flush()
 
-    _runc = " ".join([cab["binary"] + tfile.name])
+    _runc = " ".join([cab["binary"], tfile.name])
     try:
         subprocess.check_call(shlex.split(_runc))
     finally: