diff --git a/README.md b/README.md
index 070703e..9908a68 100644
--- a/README.md
+++ b/README.md
@@ -138,6 +138,7 @@ It is recommended to use this file to set your user info. Alternately, you can s
   * `git unstage` / `guns` (remove from index) and `git uncommit` / `gunc` (revert to the time prior to the last commit - dangerous if already pushed) aliases
   * Some sensible default configs, such as improving merge messages, push only pushes the current branch, removing status hints, and using mnemonic prefixes in diff: (i)ndex, (w)ork tree, (c)ommit and (o)bject
   * Slightly improved colors for diff
+  * `gdmb` (g)it (d)elete (m)erged (b)ranches - Deletes all branches already merged on current branch
 
 ### RubyGems
 
diff --git a/zsh/aliases.zsh b/zsh/aliases.zsh
index 6e5bc0a..63ddc18 100644
--- a/zsh/aliases.zsh
+++ b/zsh/aliases.zsh
@@ -128,6 +128,7 @@ alias gsmu='git submodule update'
 alias gt='git t'
 alias gbg='git bisect good'
 alias gbb='git bisect bad'
+alias gdmb='git branch --merged | grep -v "\*" | xargs -n 1 git branch -d'
 
 # Common shell functions
 alias less='less -r'