diff --git a/completions_powershell.go b/completions_powershell.go
index a0f271a..ea55e56 100644
--- a/completions_powershell.go
+++ b/completions_powershell.go
@@ -9,11 +9,82 @@ import (
 
 func WritePowerShellCompletions(out io.Writer, rootCmd *Command) error {
 	return powerShellTpl.Execute(out, map[string]any{
-		"rootCmd":    rootCmd,
-		"globalOpts": opt.Globals(),
+		"RootCmd":    rootCmd,
+		"GlobalOpts": opt.Globals(),
 	})
 }
 
-var powerShellTpl = template.Must(template.New("PowerShell").Parse(`
-	
+var powerShellTpl = template.Must(template.New("PowerShell").Funcs(tplFuncs).Parse(`
+{{- $rootCmd := .RootCmd -}}
+{{- $progName := $rootCmd.Name -}}
+{{- $varName := $rootCmd.Name | camel -}}
+
+{{- define "cmd" -}}
+{{- $progName := .ProgName -}}
+{{- if .Cmd.IsRoot }}
+{{- /**/}}            '{{ $progName }}' {
+{{- else }}
+{{- /**/}}            '{{ $progName }};{{ join (split .Cmd.CommandPath " ") ";" }}' {
+{{- end -}}
+{{- range .Cmd.Opts -}}
+{{ if ne .Name "" }}
+                [CompletionResult]::new('--{{ .Name }}', '{{ .Name }}', [CompletionResultType]::ParameterName, '{{ .Description }}')
+{{- end -}}
+{{- if ne .ShortName "" }}
+                [CompletionResult]::new('-{{ .ShortName }}', '{{ .ShortName }}', [CompletionResultType]::ParameterName, '{{ .Description }}')
+{{- end -}}
+{{- end }}
+{{- range .Cmd.Subcommands }}
+                [CompletionResult]::new('{{ .Name }}', '{{ .Name }}', [CompletionResultType]::ParameterValue, '{{ .ShortDescription }}')
+{{- end }}
+                break;
+            }
+{{- range .Cmd.Subcommands }}
+{{ template "cmd" (map "Cmd" . "ProgName" $progName) }}
+{{- end -}}
+{{- end -}}
+using namespace System.Management.Automation
+using namespace System.Management.Automation.Language
+
+[scriptblock]$__{{ $varName }}CompleterBlock = {
+    param(
+        $wordToComplete,
+        $commandAst,
+        $cursorPosition
+    )
+
+    $commandElements
+    $command = @(
+        '{{ $progName }}'
+        for ($i = 1; $i -lt $commandElements.Count; $i++) {
+            $element = $commandElements[$i]
+            if ($element -isnot [StringConstantExpressionAst] -or
+                $element.StringConstantType -ne [StringConstantType]::BareWord -or
+                $element.Value.StartsWith('-') -or
+                $element.Value -eq $wordToComplete) {
+                break
+            }
+            $element.Value
+        }
+    ) -join ';'
+
+    $completions = @(
+        switch ($command) {
+{{ template "cmd" (map "Cmd" $rootCmd "ProgName" $progName) }}
+        }
+{{- range .GlobalOpts -}}
+{{- if ne .Name "" }}
+        [CompletionResult]::new('--{{ .Name }}', '{{ .Name }}', [CompletionResultType]::ParameterName, '{{ .Description }}')
+{{- end -}}
+{{- if ne .ShortName "" }}
+        [CompletionResult]::new('-{{ .ShortName }}', '{{ .ShortName }}', [CompletionResultType]::ParameterName, '{{ .Description }}')
+{{- end -}}
+{{- end -}}
+    )
+
+    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
+        Sort-Object -Property ListItemText
+}
+
+Register-ArgumentCompleter -CommandName {{ $progName }} -ScriptBlock $__{{ $varName }}CompleterBlock
 `))
diff --git a/completions_zsh.go b/completions_zsh.go
index 50f0cf7..3f0d286 100644
--- a/completions_zsh.go
+++ b/completions_zsh.go
@@ -38,8 +38,12 @@ var zshTpl = template.Must(template.New("zsh").Funcs(tplFuncs).Parse(`
   _arguments
   {{- end -}}
   {{- range .Cmd.Opts -}}
-    {{ " " }}\
+    {{- if ne .Name ""}} \
+    '--{{ .Name }}[{{ .Description }}]'
+    {{- end }}
+    {{- if ne .ShortName ""}} \
     '-{{ .ShortName }}[{{ .Description }}]'
+    {{- end }}
   {{- end }}
   {{- if gt (len .Cmd.Subcommands) 0 -}}
     {{ " " }}\
@@ -63,6 +67,18 @@ var zshTpl = template.Must(template.New("zsh").Funcs(tplFuncs).Parse(`
 
 function _{{ $varName }} {
   {{ template "cmd" (map "Cmd" .RootCmd) -}}
+
+  {{- if gt (len .GlobalOpts) 0 }}
+  _arguments
+    {{- range .GlobalOpts -}}
+      {{- if ne .Name ""}} \
+      '--{{ .Name }}[{{ .Description }}]'
+      {{- end }}
+      {{- if ne .ShortName ""}} \
+      '-{{ .ShortName }}[{{ .Description }}]'
+      {{- end }}
+    {{- end }}
+  {{- end }}
 }
 
 compdef _{{ $varName }} {{ $progName }}
diff --git a/go.mod b/go.mod
index f6fed3c..3aac729 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module go.fifitido.net/cmd
 
 go 1.21.3
+
+require github.com/iancoleman/strcase v0.3.0
diff --git a/go.sum b/go.sum
index e69de29..6261b6a 100644
--- a/go.sum
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/iancoleman/strcase v0.3.0 h1:nTXanmYxhfFAMjZL34Ov6gkzEsSJZ5DbhxWjvSASxEI=
+github.com/iancoleman/strcase v0.3.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
diff --git a/tpl_funcs.go b/tpl_funcs.go
index 834f3a4..ab29b83 100644
--- a/tpl_funcs.go
+++ b/tpl_funcs.go
@@ -4,11 +4,14 @@ import (
 	"fmt"
 	"strings"
 	"text/template"
+
+	"github.com/iancoleman/strcase"
 )
 
 var tplFuncs = template.FuncMap{
 	"map":       tplMap,
 	"cat":       tplCat,
+	"split":     tplSplit,
 	"join":      tplJoin,
 	"under":     tplUnder,
 	"varPrefix": tplVarPrefix,
@@ -19,6 +22,8 @@ var tplFuncs = template.FuncMap{
 	"sub":       tplSub,
 	"dec":       tplDec,
 	"mult":      tplMult,
+	"pascal":    tplPascal,
+	"camel":     tplCamel,
 }
 
 func tplMap(vals ...any) (map[string]any, error) {
@@ -37,12 +42,16 @@ func tplCat(strs ...string) string {
 	return strings.Join(strs, "")
 }
 
+func tplSplit(s string, sep string) []string {
+	return strings.Split(s, sep)
+}
+
 func tplJoin(strs []string, sep string) string {
 	return strings.Join(strs, sep)
 }
 
 func tplUnder(s string) string {
-	return strings.ToLower(strings.ReplaceAll(strings.ReplaceAll(s, " ", "_"), "-", "_"))
+	return strcase.ToSnake(s)
 }
 
 func tplVarPrefix(s string) string {
@@ -80,3 +89,11 @@ func tplDec(i int) int {
 func tplMult(a, b int) int {
 	return a * b
 }
+
+func tplPascal(s string) string {
+	return strcase.ToCamel(s)
+}
+
+func tplCamel(s string) string {
+	return strcase.ToLowerCamel(s)
+}