diff --git a/doc_src/cmds/fish_git_prompt.rst b/doc_src/cmds/fish_git_prompt.rst
index 632b63136..5569b3797 100644
--- a/doc_src/cmds/fish_git_prompt.rst
+++ b/doc_src/cmds/fish_git_prompt.rst
@@ -8,7 +8,7 @@ Synopsis
 
 .. synopsis::
 
-    fish_git_prompt
+    fish_git_prompt [FORMAT]
 
 ::
 
@@ -24,6 +24,8 @@ The ``fish_git_prompt`` function displays information about the current git repo
 
 `Git <https://git-scm.com>`_ must be installed.
 
+It is possible to modify the output format by passing an argument. The default value is ``" (%s)"``.
+
 There are numerous customization options, which can be controlled with git options or fish variables. git options, where available, take precedence over the fish variable with the same function. git options can be set on a per-repository or global basis. git options can be set with the ``git config`` command, while fish variables can be set as usual with the :doc:`set <set>` command.
 
 Boolean options (those which enable or disable something) understand "1", "yes" or "true" to mean true and every other value to mean false.