diff --git a/Completion/Redhat/Command/_yum b/Completion/Redhat/Command/_yum
index f453806..722f0f5 100644
--- a/Completion/Redhat/Command/_yum
+++ b/Completion/Redhat/Command/_yum
@@ -53,6 +53,18 @@ _yum()
 		"shell:enter the 'yum shell'"
 		"update:update one or more packages"
 		"upgrade:upgrade one or more packages"
+		"update-to:update one or more packages taking obsoletes into account"
+		"upgrade-to:upgrade one or more packages taking obsoletes into account"
+		"history:view past transactions"
+		"help:produce help for all or given command"
+		"load-transaction:load a saved transaction from a textfile"
+		"load-ts:load a saved transaction from a textfile"
+		"check:Check for problems in the rpmdb"
+		"reinstall:reinstall a package"
+		"downgrade:downgrade a package"
+		"repolist:Display the configured software repositories"
+		"distribution-synchronization:Synchronize installed packages to the latest available versions"
+		"distro-sync:Synchronize installed packages to the latest available versions"
   	)
 
   	if (( CURRENT == 1 )); then
@@ -66,6 +78,10 @@ _yum()
 			remove) cmd="erase";;
 			whatprovides) cmd="provides";;
 			upgrade) cmd="update";;
+			upgrade-to) cmd="update";;
+			update-to) cmd="update";;
+			load-ts) cmd="load-transaction";;
+			distro-sync) cmd="distribution-synchronization";;
 		esac
 		
     	if (( $#cmd )); then
@@ -77,7 +93,17 @@ _yum()
 				zstyle ":completion:${curcontext}:" cache-policy _yum_caching_policy
 	  		fi
 
+		    if [ "$cmd" = "help" ]; then
+		      if (( CURRENT == 2 )); then
+		        local -a _yum_cmd_names
+		        _yum_cmd_names=(${_yum_cmds%%:*})
+		        _describe -t commands 'commands' _yum_cmd_names
+		      else
+		        _message 'no more arguments'
+		      fi
+		    else
       		_call_function ret _yum_$cmd || _message 'no more arguments'
+		    fi
     	else
       		_message "unknown yum command: $words[1]"
     	fi
@@ -85,6 +111,92 @@ _yum()
   	fi
 }
 
+# Expand next argument after 'yum check'
+_yum_check() {
+  if (( CURRENT == 2 )); then
+    local -a chkargs
+    #chkargs=("dependencies" "duplicates" "obsoletes" "provides" "all") # according to man page
+    #chkargs=("dependencies" "duplicates" "all") # according to help
+    chkargs=("dependencies" "duplicates" "provides" "all") # what works for me
+    _describe -t arguments 'check arguments' chkargs
+  fi
+  return 0
+}
+
+# Expand next argument after 'yum repolist'
+_yum_repolist() {
+  if (( CURRENT == 2 )); then
+    local -a suggests
+    suggests=("all" "enabled" "disabled")
+    _describe -t arguments 'repolist arguments' suggests
+  fi
+  return 0
+}
+
+_ids() {
+  # the last argument will be the first valid transaction ID to be suggested
+  # all other arguments are forwarded to compadd
+  #
+  # maxid is the last transaction ID known to yum
+  # minusone is the number of arguments provided to _ids minus one
+  local maxid
+  local minusone
+
+  maxid=$(yum history stats | grep Transactions | sed "s/.*: //")
+  ((minusone=$#-1))
+  compadd "${(@)@[1,$minusone]}" $(echo {$@[$#]..$maxid})
+}
+
+_ranges() {
+  if compset -P '*..'; then
+    _ids ${(S)IPREFIX#..}
+  else
+    _ids -S '..' 1
+  fi
+}
+
+# Expand next argument after 'yum history'
+_yum_history() {
+  if (( CURRENT == 2 )); then
+    local -a historycommands
+    historycommands=('info' 'list' 'packages-list' 'packages-info' 'summary' 'addon-info' 'redo' 'undo' 'roll-back' 'new' 'sync' 'stats')
+    _describe -t commands 'yum history command' historycommands
+  fi
+  if (( CURRENT == 3 )); then
+    local -a ID_commands
+    local -a ID_range_commands
+    local -a package_commands
+    local -a alts
+    alts=()
+    #ID_commands=('summary' 'info' 'list' 'stats' 'addon-info')
+    ID_commands=('addon-info')
+    ID_range_commands=('summary' 'info' 'list' 'stats')
+    package_commands=('summary' 'info' 'list' 'stats' 'packages-list' 'packages-info')
+    #package_commands=('packages-list' 'packages-info')
+    # packages-list, packages-info   : needs package name
+    # summary, info, list, stats     : ID, ID range, package name
+    # addon-info                     : ID
+    # redo, undo, roll-back, sync    : unknown
+
+    [[ -n "${ID_commands[(r)$words[2]]}" ]] && alts+=('special:special IDs:(last)')
+    [[ -n "${ID_commands[(r)$words[2]]}" ]] && alts+=('regular:IDs:_ids 1')
+    [[ -n "${ID_range_commands[(r)$words[2]]}" ]] && alts+=('regular:transaction ranges:_ranges')
+    [[ -n "${ID_range_commands[(r)$words[2]]}" ]] && alts+=('special:all transactions:(all)')
+    [[ -n "${package_commands[(r)$words[2]]}" ]] && alts+=("packages:packages:_yum_act_on_installed_pkgs")
+
+    (( ${+alts[1]} )) && _alternative "$alts[@]" || \
+      _message "unknown expansion for: yum history $words[2]"
+  fi
+  if (( CURRENT == 4 )); then
+    if [ "$words[2]" = "addon-info" ]; then
+      local -a historyargs
+      historyargs=(saved_tx)
+      _describe 'additional option' historyargs
+    fi
+  fi
+}
+
+
 # Fills the all pkg cache
 _yum_all_pkgs()
 {
@@ -163,11 +275,34 @@ yum_repos() {
 	compadd "$@" -a -- enabled_yum_repos
 }
 
+# Suggest installed packages
+_yum_act_on_installed_pkgs() {
+	_yum_installed_pkgs
+	compadd "$@" -a -- _installed_pkgs
+}
+
+# Completion function for distribution-synchronization|distro-sync
+(( $+functions[_yum_distribution-synchronization] )) || _yum_distribution-synchronization()
+{
+  _yum_act_on_installed_pkgs "$@"
+}
+
 # Completion function for erase|remove
 (( $+functions[_yum_erase] )) || _yum_erase()
 {
-	_yum_installed_pkgs
-	compadd "$@" -a -- _installed_pkgs
+  _yum_act_on_installed_pkgs "$@"
+}
+
+# Completion function for downgrade
+(( $+functions[_yum_downgrade] )) || _yum_downgrade()
+{
+  _yum_act_on_installed_pkgs "$@"
+}
+
+# Completion function for reinstall
+(( $+functions[_yum_reinstall] )) || _yum_reinstall()
+{
+  _yum_act_on_installed_pkgs "$@"
 }
 
 # Completion function for install
@@ -191,6 +326,12 @@ yum_repos() {
         return ret
 }
 
+# Completion function for load-transaction
+(( $+functions[_yum_load-transaction] )) || _yum_load-transaction()
+{
+	_files
+}
+
 # Completion function for localinstall
 (( $+functions[_yum_localinstall] )) || _yum_localinstall()
 {