Moffat was speaking via Twitter, the micro-blogging service available on PCs, mobiles and games consoles.
David Tennant announced his decision to leave Doctor Who in 2008, although apparently wobbled in his decision to leave when Moffat tried to convince the Tenth Doctor actor to stay.
Apparently Steven Moffat is targeted by a sole David Tennant fan, to general bewilderment.
“I don’t get much hate mail, but when I do it’s always from a lady David Tennant fan. Why?
“He’s a mate of mine and everything!”
Tennant last appeared in The End of Time, Part 2 on New Year’s Day, and is currently filming romantic comedy Decoy Bride.
Meanwhile, you can follow Steven Moffat on Twitter via @steven_moffat.