diff --git a/cmd/completion.go b/cmd/completion.go
index 4aa4a78..b05dcde 100644
--- a/cmd/completion.go
+++ b/cmd/completion.go
@@ -19,28 +19,37 @@ func newCompletionCmd(driver summon.Lister) *cobra.Command {
 	}
 
 	c := &cobra.Command{
-		Use:   "completion",
-		Short: "Output bash completion script",
-		Long: `To load completion run
+		Use:   "completion [bash|zsh]",
+		Short: "Generate completion script",
+		Long: `To load completion, run
 
-. <(summon completion)
+. <(summon completion bash)
+
+or
+
+. <(summon completion zsh)
 
 To configure your bash shell to load completions for each session add to your bashrc
 
 # ~/.bashrc or ~/.profile
-. <(summon completion)
+. <(summon completion bash)
+
+# ~/.zshrc
+. <(summon completion zsh)
 `,
+		ValidArgs: []string{"bash", "zsh"},
+		Args:      cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			cOpts.out = cmd.OutOrStdout()
 			cOpts.cmd = cmd
-			return cOpts.run()
+			return cOpts.run(args[0])
 		},
 	}
 
 	return c
 }
 
-func (c completionCmdOpts) run() error {
+func (c completionCmdOpts) run(shell string) error {
 	list, err := c.driver.List()
 	if err != nil {
 		return err
@@ -54,6 +63,12 @@ func (c completionCmdOpts) run() error {
 		})
 	}
 
-	// TODO support other shells
-	return c.cmd.Root().GenBashCompletionV2(c.out, true)
+	switch shell {
+	case "bash":
+		return c.cmd.Root().GenBashCompletionV2(c.out, true)
+	case "zsh":
+		return c.cmd.Root().GenZshCompletion(c.out)
+	}
+
+	return nil
 }
diff --git a/cmd/completion_test.go b/cmd/completion_test.go
index 43f6d74..0eac722 100644
--- a/cmd/completion_test.go
+++ b/cmd/completion_test.go
@@ -4,19 +4,41 @@ import (
 	"bytes"
 	"testing"
 
-	"github.com/davidovich/summon/pkg/summon"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCompletionCommand(t *testing.T) {
-	s, _ := summon.New(cmdTestFS)
+	tt := []struct {
+		name      string
+		args      []string
+		want      string
+		assertion assert.ComparisonAssertionFunc
+	}{
+		{
+			name:      "bash",
+			args:      []string{"completion", "bash"},
+			want:      "# bash completion V2 for summon",
+			assertion: assert.Contains,
+		},
+		{
+			name:      "zsh",
+			args:      []string{"completion", "zsh"},
+			want:      "compdef _summon summon",
+			assertion: assert.Contains,
+		},
+	}
 
-	cmd := newCompletionCmd(s)
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			_, rootCmd := makeRootCmd(false, tc.args...)
 
-	b := &bytes.Buffer{}
+			b := &bytes.Buffer{}
 
-	cmd.SetOutput(b)
-	cmd.Execute()
+			rootCmd.SetOut(b)
+			err := rootCmd.Execute()
 
-	assert.Contains(t, b.String(), "# bash completion V2 for completion")
+			assert.NoError(t, err)
+			tc.assertion(t, b.String(), tc.want)
+		})
+	}
 }
diff --git a/cmd/root_test.go b/cmd/root_test.go
index 90bcee1..a90f95a 100644
--- a/cmd/root_test.go
+++ b/cmd/root_test.go
@@ -66,7 +66,7 @@ func Test_createRootCmd(t *testing.T) {
 		},
 		{
 			name:     "completion_run",
-			rootCmd:  makeRootCmd("completion"),
+			rootCmd:  makeRootCmd("completion", "bash"),
 			expected: "# bash completion V2 for summon",
 		},
 		{