diff --git a/README.md b/README.md
index 9065994..4f8d6d5 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ An alternative to [z.sh](https://github.com/rupa/z) with windows and posix shell
 
 - **10x** times faster than **fasd** and **autojump**
 - **3x** times faster than **z.sh**
-- supports **posix shells**: bash, zsh, dash, sh, busybox, and etc.
+- compatible with **posix shells**: bash, zsh, dash, sh, ash, busybox and etc.
 - supports Windows cmd (with clink) and cmder
 - self contained, no dependence on awk/gawk
 
diff --git a/z.lua b/z.lua
index ec7bac6..449ebc0 100644
--- a/z.lua
+++ b/z.lua
@@ -8,7 +8,8 @@
 --
 -- * 10x times faster than fasd and autojump
 -- * 3x times faster than rupa/z
--- * supports: Bash, Zsh, Posix shells and Windows cmd
+-- * compatible with posix shells: bash, zsh, sh, ash, dash, busybox
+-- * supports windows
 --
 -- USE:
 --     * z foo     # cd to most frecent dir matching foo
@@ -1223,11 +1224,28 @@ function z_shell_init(opts)
 			print(script_init_zsh)
 		end
 		print(script_complete_zsh)
-	else
+	elseif opts.posix ~= nil then
 		if prompt_hook then
 			print(script_init_posix)
 		end
 		print('_ZL_NOBUILTIN=1')
+	else
+		print('if [ -n "$BASH_VERSION" ]; then')
+		if prompt_hook then
+			print(script_init_bash)
+		end
+		print(script_complete_bash)
+		print('elif [ -n "$ZSH_VERSION" ]; then')
+		if prompt_hook then
+			print(script_init_zsh)
+		end
+		-- print(script_complete_zsh)
+		print('else')
+		if prompt_hook then
+			print(script_init_posix)
+		end
+		print('_ZL_NOBUILTIN=1')
+		print('fi')
 	end
 end