diff --git a/tmux.1 b/tmux.1
index e38cb185..41f6057c 100644
--- a/tmux.1
+++ b/tmux.1
@@ -829,13 +829,13 @@ is given.
 and
 .Ar shell-command
 are the name of and shell command to execute in the initial window.
-If
-.Fl d
-is used,
+With
+.Fl d ,
+the initial size is 80 x 24;
 .Fl x
 and
 .Fl y
-specify the size of the initial window.
+can be used to specify a different size.
 .Pp
 If run from a terminal, any
 .Xr termios 4