diff --git a/lib/completion.zsh b/lib/completion.zsh
index 98556f25b..a829e9682 100644
--- a/lib/completion.zsh
+++ b/lib/completion.zsh
@@ -35,10 +35,12 @@ zstyle ':completion:*:cd:*' tag-order local-directories directory-stack path-dir
 cdpath=(.)
 
 # use /etc/hosts and known_hosts for hostname completion
+[ -f ~/.ssh/config ] && : ${(A)ssh_config_hosts:=${${${${(@M)${(f)"$(<~/.ssh/config)"}:#Host *}#Host }:#*\**}:#*\?*}}
 [ -r ~/.ssh/known_hosts ] && _ssh_hosts=(${${${${(f)"$(<$HOME/.ssh/known_hosts)"}:#[\|]*}%%\ *}%%,*}) || _ssh_hosts=()
 [ -r ~/.host-completion ] && : ${(A)_host_completion:=${(s: :)${(ps:\t:)${${(f)~~"$(<~/.host-completion)"}%%\#*}##[:blank:]#[^[:blank:]]#}}} || _host_completion=()
 [ -r /etc/hosts ] && : ${(A)_etc_hosts:=${(s: :)${(ps:\t:)${${(f)~~"$(</etc/hosts)"}%%\#*}##[:blank:]#[^[:blank:]]#}}} || _etc_hosts=()
 hosts=(
+  "$_ssh_config_hosts[@]"
   "$_ssh_hosts[@]"
   "$_etc_hosts[@]"
   "$_host_completion[@]"
@@ -53,14 +55,11 @@ zstyle ':completion::complete:*' cache-path ~/.oh-my-zsh/cache/
 
 # Don't complete uninteresting users
 zstyle ':completion:*:*:*:users' ignored-patterns \
-        adm amanda apache avahi beaglidx bin cacti canna clamav daemon \
-        dbus distcache dovecot fax ftp games gdm gkrellmd gopher \
-        hacluster haldaemon halt hsqldb ident junkbust ldap lp mail \
-        mailman mailnull mldonkey mysql nagios \
-        named netdump news nfsnobody nobody nscd ntp nut nx openvpn \
-        operator pcap postfix postgres privoxy pulse pvm quagga radvd \
-        rpc rpcuser rpm shutdown squid sshd sync uucp vcsa xfs
+        $(awk -F: '/^_/ { print $1 }' /etc/passwd)
 
+zstyle ':completion:*:*:*:groups' ignored-patterns \
+        $(awk -F: '/^_/ { print $1 }' /etc/group)
+    
 # ... unless we really want to.
 zstyle '*' single-ignored show