--- a/src/SubSpace.cc
+++ b/src/SubSpace.cc
@@ -18,7 +18,7 @@
 
 DEFUN_DLD (SubSpace, args, , "-*- texinfo -*-\n\
 @deftypefn {Function File} {[@var{V1}]} = \
-SubSpace (@var{Space V}, @var{index}(Optional)) \n\
+SubSpace (@var{Space V}, @var{index}) \n\
 Extract a SubSpace from an object of type FunctionSpace. \n\
 The input arguments are\n\
 @itemize @bullet\n\