diff --git a/bfps/__main__.py b/bfps/__main__.py
index 3efadc7b3f76325b0b7a3933437aedeea390910b..baa0b4033732659dab3ad338b83408060b88b4f7 100644
--- a/bfps/__main__.py
+++ b/bfps/__main__.py
@@ -50,7 +50,7 @@ def main():
     # error is thrown if first option is not a base class, so Launcher
     # cannot be executed by mistake.
     c = eval('{0}()'.format(opt.base_class))
-    c.launch(sys.argv[2:])
+    c.launch(args = sys.argv[2:])
     return None
 
 if __name__ == '__main__':
diff --git a/bfps/_fluid_base.py b/bfps/_fluid_base.py
index 6fb0db9042198d98648ef52e83344747b5c0dfcf..8c313b05f57f44d2f555a4ae53c440e958f5da29 100644
--- a/bfps/_fluid_base.py
+++ b/bfps/_fluid_base.py
@@ -398,6 +398,7 @@ class _fluid_particle_base(_code):
         return None
     def launch(
             self,
+            args = [],
             **kwargs):
         return None