diff --git a/docs/source/io_formats/settings.rst b/docs/source/io_formats/settings.rst
index 285dfa2290..a162e8de6d 100644
--- a/docs/source/io_formats/settings.rst
+++ b/docs/source/io_formats/settings.rst
@@ -768,9 +768,10 @@ certain surfaces and write out the source bank in a separate file called
     *Default*: None
 
   :mcpl:
-    An optional boolean which indicates if the banked particle should
+    An optional boolean which indicates if the banked particles should
     be written to a file in the MCPL-format (documented in mcpl_).
-    instead of the native hdf5-based format.
+    instead of the native hdf5-based format.If activated the output
+    output file name is altered to ``surface_source.mcpl``
 
     *Default*: false