diff --git a/README.mkd b/README.mkd
index f7819d0..2e442d2 100644
--- a/README.mkd
+++ b/README.mkd
@@ -127,6 +127,9 @@ Add `let g:gitgutter_highlight_lines = 1` to your `~/.vimrc`.
 
 Your colorscheme is configuring the `SignColumn` highlight group weirdly.  Please see the section above on customising the sign column.
 
+> Why is no sign shown if I delete the first line(s) in a file?
+
+vim-gitgutter shows removed lines with a sign on the line above.  In this case there isn't a line above so vim-gitgutter can't show the sign.
 
 > What happens if I also use another plugin which uses signs (e.g. Syntastic)?
 
diff --git a/doc/gitgutter.txt b/doc/gitgutter.txt
index c4ca284..30bc6ff 100644
--- a/doc/gitgutter.txt
+++ b/doc/gitgutter.txt
@@ -166,8 +166,12 @@ a. Why are the colours in the sign column weird?
   Your colorscheme is configuring the |hl-SignColumn| highlight group weirdly.
   Please see |GitGutterCustomisation| on customising the sign column.
 
+b. Why is no sign shown if I delete the first line(s) in a file?
 
-b. What happens if I also use another plugin which uses signs (e.g. Syntastic)?
+  vim-gitgutter shows removed lines with a sign on the line above.  In this
+  case there isn't a line above so vim-gitgutter can't show the sign.
+
+c. What happens if I also use another plugin which uses signs (e.g. Syntastic)?
 
   Vim only allows one sign per line. Before adding a sign to a line,
   vim-gitgutter checks whether a sign has already been added by somebody else.