diff --git a/contrib/completion/fish/docker.fish b/contrib/completion/fish/docker.fish
index 48b0279cee..b250dfd0b1 100644
--- a/contrib/completion/fish/docker.fish
+++ b/contrib/completion/fish/docker.fish
@@ -185,7 +185,7 @@ complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -s l -l latest -d '
 complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -s n -d 'Show n last created containers, include non-running ones.'
 complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -l no-trunc -d "Don't truncate output"
 complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -s q -l quiet -d 'Only display numeric IDs'
-complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -s s -l size -d 'Display sizes'
+complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -s s -l size -d 'Display total file sizes'
 complete -c docker -A -f -n '__fish_seen_subcommand_from ps' -l since -d 'Show only containers created since Id or Name, include non-running ones.'
 
 # pull
diff --git a/contrib/completion/zsh/_docker b/contrib/completion/zsh/_docker
index 4c0937e10c..f867d76a78 100644
--- a/contrib/completion/zsh/_docker
+++ b/contrib/completion/zsh/_docker
@@ -357,7 +357,7 @@ __docker_subcommand () {
                 '-n[Show n last created containers, include non-running one]:n:(1 5 10 25 50)' \
                 '--no-trunc[Do not truncate output]' \
                 {-q,--quiet}'[Only show numeric IDs]' \
-                {-s,--size}'[Display sizes]' \
+                {-s,--size}'[Display total file sizes]' \
                 '--since=-[Show only containers created since...]:containers:__docker_containers'
             ;;
         (tag)
diff --git a/docs/sources/reference/commandline/cli.md b/docs/sources/reference/commandline/cli.md
index 7526954b12..ab80f2ff51 100644
--- a/docs/sources/reference/commandline/cli.md
+++ b/docs/sources/reference/commandline/cli.md
@@ -1068,7 +1068,7 @@ for further details.
       -n=-1                 Show n last created containers, include non-running ones.
       --no-trunc=false      Don't truncate output
       -q, --quiet=false     Only display numeric IDs
-      -s, --size=false      Display sizes
+      -s, --size=false      Display total file sizes
       --since=""            Show only containers created since Id or Name, include non-running ones.
 
 Running `docker ps` showing 2 linked containers.