diff --git a/lib/functions.zsh b/lib/functions.zsh
index 63ab755cf..ff538c88d 100644
--- a/lib/functions.zsh
+++ b/lib/functions.zsh
@@ -7,7 +7,7 @@ function uninstall_oh_my_zsh() {
 }
 
 function upgrade_oh_my_zsh() {
-  /usr/bin/env ZSH=$ZSH /bin/sh $ZSH/tools/upgrade.sh
+  /usr/bin/env ZSH=$ZSH /bin/bash $ZSH/tools/upgrade.sh
 }
 
 function take() {
diff --git a/tools/check_for_upgrade.sh b/tools/check_for_upgrade.sh
index 581f03a07..1759cd366 100644
--- a/tools/check_for_upgrade.sh
+++ b/tools/check_for_upgrade.sh
@@ -9,7 +9,7 @@ function _update_zsh_update() {
 }
 
 function _upgrade_zsh() {
-  /usr/bin/env ZSH=$ZSH /bin/sh $ZSH/tools/upgrade.sh
+  /usr/bin/env ZSH=$ZSH /bin/bash $ZSH/tools/upgrade.sh
   # update the zsh file
   _update_zsh_update
 }
diff --git a/tools/upgrade.sh b/tools/upgrade.sh
index 0aeebdebf..896900ef8 100644
--- a/tools/upgrade.sh
+++ b/tools/upgrade.sh
@@ -3,8 +3,9 @@ current_path=${current_path/ /\\ }
 printf '\033[0;34m%s\033[0m\n' "Upgrading Oh My Zsh"
 cd "$ZSH"
 
-if git pull origin master
+if git fetch origin
 then
+  git rebase origin/master
   printf '\033[0;32m%s\033[0m\n' '         __                                     __   '
   printf '\033[0;32m%s\033[0m\n' '  ____  / /_     ____ ___  __  __   ____  _____/ /_  '
   printf '\033[0;32m%s\033[0m\n' ' / __ \/ __ \   / __ `__ \/ / / /  /_  / / ___/ __ \ '