diff --git a/app_test.go b/app_test.go
index 5f20078..26ae28a 100644
--- a/app_test.go
+++ b/app_test.go
@@ -228,6 +228,7 @@ func ExampleApp_Run_subcommandNoAction() {
 }
 
 func ExampleApp_Run_bashComplete_withShortFlag() {
+	os.Setenv("SHELL", "bash")
 	os.Args = []string{"greet", "-", "--generate-bash-completion"}
 
 	app := NewApp()
@@ -255,6 +256,7 @@ func ExampleApp_Run_bashComplete_withShortFlag() {
 }
 
 func ExampleApp_Run_bashComplete_withLongFlag() {
+	os.Setenv("SHELL", "bash")
 	os.Args = []string{"greet", "--s", "--generate-bash-completion"}
 
 	app := NewApp()
@@ -283,6 +285,7 @@ func ExampleApp_Run_bashComplete_withLongFlag() {
 	// --similar-flag
 }
 func ExampleApp_Run_bashComplete_withMultipleLongFlag() {
+	os.Setenv("SHELL", "bash")
 	os.Args = []string{"greet", "--st", "--generate-bash-completion"}
 
 	app := NewApp()
@@ -315,7 +318,7 @@ func ExampleApp_Run_bashComplete_withMultipleLongFlag() {
 }
 
 func ExampleApp_Run_bashComplete() {
-	// set args for examples sake
+	os.Setenv("SHELL", "bash")
 	os.Args = []string{"greet", "--generate-bash-completion"}
 
 	app := &App{
diff --git a/autocomplete/zsh_autocomplete b/autocomplete/zsh_autocomplete
index ee1b562..b519666 100644
--- a/autocomplete/zsh_autocomplete
+++ b/autocomplete/zsh_autocomplete
@@ -1,16 +1,20 @@
 #compdef $PROG
 
-local -a opts
-local cur
-cur=${words[-1]}
-if [[ "$cur" == "-"* ]]; then
-  opts=("${(@f)$(${words[@]:0:#words[@]-1} ${cur} --generate-bash-completion)}")
-else
-  opts=("${(@f)$(${words[@]:0:#words[@]-1} --generate-bash-completion)}")
-fi
+_cli_zsh_autocomplete() {
+  local -a opts
+  local cur
+  cur=${words[-1]}
+  if [[ "$cur" == "-"* ]]; then
+    opts=("${(@f)$(${words[@]:0:#words[@]-1} ${cur} --generate-bash-completion)}")
+  else
+    opts=("${(@f)$(${words[@]:0:#words[@]-1} --generate-bash-completion)}")
+  fi
 
-if [[ "${opts[1]}" != "" ]]; then
-  _describe 'values' opts
-else
-  _files
-fi
+  if [[ "${opts[1]}" != "" ]]; then
+    _describe 'values' opts
+  else
+    _files
+  fi
+}
+
+compdef _cli_zsh_autocomplete $PROG
diff --git a/docs/v2/manual.md b/docs/v2/manual.md
index 3d96bb8..fd5656a 100644
--- a/docs/v2/manual.md
+++ b/docs/v2/manual.md
@@ -1165,10 +1165,10 @@ func main() {
 ```
 
 #### ZSH Support
-Auto-completion for ZSH is also supported using the `autocomplete/zsh_autocomplete` 
-file included in this repo. One environment variable is used, `PROG`.  Set 
-`PROG` to the program name as before, and then `source path/to/autocomplete/zsh_autocomplete`. 
-Adding the following lines to your ZSH configuration file (usually `.zshrc`) 
+Auto-completion for ZSH is also supported using the `autocomplete/zsh_autocomplete`
+file included in this repo. One environment variable is used, `PROG`.  Set
+`PROG` to the program name as before, and then `source path/to/autocomplete/zsh_autocomplete`.
+Adding the following lines to your ZSH configuration file (usually `.zshrc`)
 will allow the auto-completion to persist across new shells:
 
 ```
diff --git a/help_test.go b/help_test.go
index 98530dd..17a263d 100644
--- a/help_test.go
+++ b/help_test.go
@@ -1040,12 +1040,16 @@ func TestHideHelpCommand_WithSubcommands(t *testing.T) {
 }
 
 func TestDefaultCompleteWithFlags(t *testing.T) {
+	origEnv := os.Environ()
 	origArgv := os.Args
 
 	t.Cleanup(func() {
 		os.Args = origArgv
+		resetEnv(origEnv)
 	})
 
+	os.Setenv("SHELL", "bash")
+
 	for _, tc := range []struct {
 		name     string
 		c        *Context