diff --git a/shapes3d.scad b/shapes3d.scad
index 27522c4a..e2ebfefa 100644
--- a/shapes3d.scad
+++ b/shapes3d.scad
@@ -330,7 +330,7 @@ module cuboid(
             }
         }
     }
-    sizecheck = assert(num_defined([size,p1,p2])!=3, "\nCannot give size if p2 is given (did you forget braces on the size argument?)")
+    sizecheck = assert(num_defined([size,p1,p2])!=3, "\nCannot give size if p2 is given (did you forget brackets on the size argument?)")
                 assert(is_def(p1) || is_undef(p2), "If p2 is given you must also give p1");
     size = force_list(default(size,1),3);
     edges = _edges(edges, except=first_defined([except_edges,except]));