diff --git a/completions_powershell.go b/completions_powershell.go
index a0f271a..3c4cf4b 100644
--- a/completions_powershell.go
+++ b/completions_powershell.go
@@ -9,11 +9,23 @@ 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 := $rootCmd.Name | camel -}}
+
+[scriptblock]$__{{ $varName }}CompleterBlock = {
+    param(
+        $WordToComplete,
+        $CommandAst,
+        $CursorPosition
+    )
+}
+
+Register-ArgumentCompleter -CommandName {{ $progName }} -ScriptBlock $__{{ $varName }}CompleterBlock
 `))
diff --git a/completions_zsh.go b/completions_zsh.go
index 50f0cf7..6c12903 100644
--- a/completions_zsh.go
+++ b/completions_zsh.go
@@ -15,6 +15,7 @@ func WriteZshCompletions(out io.Writer, rootCmd *Command) error {
 }
 
 // TODO: Fix indentation and other spacing
+// TODO: Implement global options
 var zshTpl = template.Must(template.New("zsh").Funcs(tplFuncs).Parse(`
 {{- $rootCmd := .RootCmd -}}
 {{- $progName := $rootCmd.Name -}}
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..db95e70 100644
--- a/tpl_funcs.go
+++ b/tpl_funcs.go
@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"strings"
 	"text/template"
+
+	"github.com/iancoleman/strcase"
 )
 
 var tplFuncs = template.FuncMap{
@@ -19,6 +21,8 @@ var tplFuncs = template.FuncMap{
 	"sub":       tplSub,
 	"dec":       tplDec,
 	"mult":      tplMult,
+	"pascal":    tplPascal,
+	"camel":     tplCamel,
 }
 
 func tplMap(vals ...any) (map[string]any, error) {
@@ -42,7 +46,7 @@ func tplJoin(strs []string, sep string) string {
 }
 
 func tplUnder(s string) string {
-	return strings.ToLower(strings.ReplaceAll(strings.ReplaceAll(s, " ", "_"), "-", "_"))
+	return strcase.ToSnake(s)
 }
 
 func tplVarPrefix(s string) string {
@@ -80,3 +84,11 @@ 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)
+}