diff --git a/Library/Homebrew/completions/bash.erb b/Library/Homebrew/completions/bash.erb
index 8a1042b2f5..a9395d3ef3 100644
--- a/Library/Homebrew/completions/bash.erb
+++ b/Library/Homebrew/completions/bash.erb
@@ -81,14 +81,14 @@ __brew_complete_installed_casks() {
 __brew_complete_outdated_formulae() {
   local cur="${COMP_WORDS[COMP_CWORD]}"
   local outdated_formulae
-  outdated_formulae="$(brew outdated --formula --quiet)"
+  outdated_formulae="$(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --formula --quiet)"
   while read -r line; do COMPREPLY+=("${line}"); done < <(compgen -W "${outdated_formulae}" -- "${cur}")
 }
 
 __brew_complete_outdated_casks() {
   local cur="${COMP_WORDS[COMP_CWORD]}"
   local outdated_casks
-  outdated_casks="$(brew outdated --cask --quiet 2>/dev/null)"
+  outdated_casks="$(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --cask --quiet 2>/dev/null)"
   while read -r line; do COMPREPLY+=("${line}"); done < <(compgen -W "${outdated_casks}" -- "${cur}")
 }
 
diff --git a/Library/Homebrew/completions/fish.erb b/Library/Homebrew/completions/fish.erb
index 95976df051..383966bb8c 100644
--- a/Library/Homebrew/completions/fish.erb
+++ b/Library/Homebrew/completions/fish.erb
@@ -108,7 +108,7 @@ end
 
 
 function __fish_brew_suggest_formulae_outdated -d "List of outdated formulae with the information about potential upgrade"
-    brew outdated --formula --verbose \
+    HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --formula --verbose 2>/dev/null \
         # replace first space with tab to make the following a description in the completions list:
         | string replace -r '\s' '\t'
 end
@@ -134,7 +134,7 @@ function __fish_brew_suggest_casks_installed -d "Lists installed casks"
 end
 
 function __fish_brew_suggest_casks_outdated -d "Lists outdated casks with the information about potential upgrade"
-    brew outdated --cask --verbose 2>/dev/null \
+    HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --cask --verbose 2>/dev/null \
         # replace first space with tab to make the following a description in the completions list:
         | string replace -r '\s' '\t'
 end
@@ -157,13 +157,10 @@ function __fish_brew_suggest_diagnostic_checks -d "List available diagnostic che
     brew doctor --list-checks
 end
 
-# TODO: any better way to list available services?
 function __fish_brew_suggest_services -d "Lists available services"
-    set -l list (brew services list)
-    set -e list[1] # Header
-    for line in $list
-        echo (string split ' ' $line)[1]
-    end
+    command find (brew --cellar) -mindepth 3 -maxdepth 3 -name '*.service' \
+      | awk -F'homebrew.|.service' '{print $3}' \
+      | sort -d
 end
 
 
diff --git a/Library/Homebrew/completions/zsh.erb b/Library/Homebrew/completions/zsh.erb
index c4c511b0e1..025ab24ea6 100644
--- a/Library/Homebrew/completions/zsh.erb
+++ b/Library/Homebrew/completions/zsh.erb
@@ -74,7 +74,7 @@ __brew_outdated_formulae() {
   [[ -prefix '-' ]] && return 0
 
   local -a formulae
-  formulae=($(brew outdated --formula))
+  formulae=($(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --formula))
   _describe -t formulae 'outdated formulae' formulae
 }
 
@@ -106,7 +106,7 @@ __brew_outdated_casks() {
   [[ -prefix '-' ]] && return 0
 
   local -a casks
-  casks=($(brew outdated --cask 2>/dev/null))
+  casks=($(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --cask 2>/dev/null))
   _describe -t casks 'outdated casks' casks
 }
 
diff --git a/completions/bash/brew b/completions/bash/brew
index 2611b88a97..d3b9b955ac 100644
--- a/completions/bash/brew
+++ b/completions/bash/brew
@@ -68,14 +68,14 @@ __brew_complete_installed_casks() {
 __brew_complete_outdated_formulae() {
   local cur="${COMP_WORDS[COMP_CWORD]}"
   local outdated_formulae
-  outdated_formulae="$(brew outdated --formula --quiet)"
+  outdated_formulae="$(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --formula --quiet)"
   while read -r line; do COMPREPLY+=("${line}"); done < <(compgen -W "${outdated_formulae}" -- "${cur}")
 }
 
 __brew_complete_outdated_casks() {
   local cur="${COMP_WORDS[COMP_CWORD]}"
   local outdated_casks
-  outdated_casks="$(brew outdated --cask --quiet 2>/dev/null)"
+  outdated_casks="$(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --cask --quiet 2>/dev/null)"
   while read -r line; do COMPREPLY+=("${line}"); done < <(compgen -W "${outdated_casks}" -- "${cur}")
 }
 
diff --git a/completions/fish/brew.fish b/completions/fish/brew.fish
index 7f55a8e283..30962f4cf1 100644
--- a/completions/fish/brew.fish
+++ b/completions/fish/brew.fish
@@ -95,7 +95,7 @@ end
 
 
 function __fish_brew_suggest_formulae_outdated -d "List of outdated formulae with the information about potential upgrade"
-    brew outdated --formula --verbose \
+    HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --formula --verbose 2>/dev/null \
         # replace first space with tab to make the following a description in the completions list:
         | string replace -r '\s' '\t'
 end
@@ -121,7 +121,7 @@ function __fish_brew_suggest_casks_installed -d "Lists installed casks"
 end
 
 function __fish_brew_suggest_casks_outdated -d "Lists outdated casks with the information about potential upgrade"
-    brew outdated --cask --verbose 2>/dev/null \
+    HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --cask --verbose 2>/dev/null \
         # replace first space with tab to make the following a description in the completions list:
         | string replace -r '\s' '\t'
 end
@@ -144,13 +144,10 @@ function __fish_brew_suggest_diagnostic_checks -d "List available diagnostic che
     brew doctor --list-checks
 end
 
-# TODO: any better way to list available services?
 function __fish_brew_suggest_services -d "Lists available services"
-    set -l list (brew services list)
-    set -e list[1] # Header
-    for line in $list
-        echo (string split ' ' $line)[1]
-    end
+    command find (brew --cellar) -mindepth 3 -maxdepth 3 -name '*.service' \
+      | awk -F'homebrew.|.service' '{print $3}' \
+      | sort -d
 end
 
 
diff --git a/completions/zsh/_brew b/completions/zsh/_brew
index d2b4dfb94a..69d5ca98ac 100644
--- a/completions/zsh/_brew
+++ b/completions/zsh/_brew
@@ -78,7 +78,7 @@ __brew_outdated_formulae() {
   [[ -prefix '-' ]] && return 0
 
   local -a formulae
-  formulae=($(brew outdated --formula))
+  formulae=($(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --formula))
   _describe -t formulae 'outdated formulae' formulae
 }
 
@@ -110,7 +110,7 @@ __brew_outdated_casks() {
   [[ -prefix '-' ]] && return 0
 
   local -a casks
-  casks=($(brew outdated --cask 2>/dev/null))
+  casks=($(HOMEBREW_NO_AUTO_UPDATE=1 brew outdated --cask 2>/dev/null))
   _describe -t casks 'outdated casks' casks
 }