diff --git a/contrib/completion/bash/docker b/contrib/completion/bash/docker
index ad48f288..ef7f0f33 100755
--- a/contrib/completion/bash/docker
+++ b/contrib/completion/bash/docker
@@ -407,7 +407,7 @@ _docker_events() {
 _docker_exec() {
 	case "$cur" in
 		-*)
-			COMPREPLY=( $( compgen -W "--detach -d --help --interactive -i -t --tty" -- "$cur" ) )
+			COMPREPLY=( $( compgen -W "--detach -d --help --interactive -i -t --tty -u --user" -- "$cur" ) )
 			;;
 		*)
 			__docker_containers_running
diff --git a/docs/sources/reference/commandline/cli.md b/docs/sources/reference/commandline/cli.md
index 10953dc2..8a780953 100644
--- a/docs/sources/reference/commandline/cli.md
+++ b/docs/sources/reference/commandline/cli.md
@@ -1121,6 +1121,7 @@ You'll need two shells for this example.
       -d, --detach=false         Detached mode: run command in the background
       -i, --interactive=false    Keep STDIN open even if not attached
       -t, --tty=false            Allocate a pseudo-TTY
+      -u, --user=                Username or UID (format: <name|uid>[:<group|gid>])
 
 The `docker exec` command runs a new command in a running container.