diff --git a/docs/reference/commandline/cli.md b/docs/reference/commandline/cli.md
index 6fd3b01107..19e37f1d97 100644
--- a/docs/reference/commandline/cli.md
+++ b/docs/reference/commandline/cli.md
@@ -20,7 +20,7 @@ or execute `docker help`:
 
 ```bash
 $ docker
-Usage: docker [OPTIONS] COMMAND [arg...]
+Usage: docker [OPTIONS] COMMAND [ARG...]
        docker [ --help | -v | --version ]
 
 A self-sufficient runtime for containers.
diff --git a/man/docker.1.md b/man/docker.1.md
index ecf048ef39..2a96184439 100644
--- a/man/docker.1.md
+++ b/man/docker.1.md
@@ -5,7 +5,7 @@
 docker \- Docker image and container command line interface
 
 # SYNOPSIS
-**docker** [OPTIONS] COMMAND [arg...]
+**docker** [OPTIONS] COMMAND [ARG...]
 
 **docker** daemon [--help|...]