diff --git a/check_for_upgrade.sh b/check_for_upgrade.sh
index e0d77dc..b4ff921 100755
--- a/check_for_upgrade.sh
+++ b/check_for_upgrade.sh
@@ -7,7 +7,8 @@ function _current_epoch() {
 }
 
 function _update_dotfiles_update() {
-  echo "LAST_EPOCH=$(_current_epoch)" >! ~/.dotfiles-update
+  echo "export LAST_EPOCH=$(_current_epoch)" > ${HOME}/.dotfiles-update
+  echo "touched ~/.dotfiles-update"
 }
 
 function _upgrade_dotfiles() {
@@ -23,19 +24,28 @@ if [[ -z "$epoch_target" ]]; then
   epoch_target=13
 fi
 
-# Cancel upgrade if the current user doesn't have write permissions for the
-# dotfiles directory.
-[[ -w "$_DOTFILES" ]] || echo "You can't write to $(dotfiles)"; return 1
+# Cancel upgrade if the current user doesn't have
+# write permissions for the dotfiles directory.
+if [[ -w "$_DOTFILES" ]]; then
+else
+  echo "You can't write to $(_dotfiles)!"
+  return 1
+fi
 
 # Cancel upgrade if git is unavailable on the system
-whence git >/dev/null || echo "git is not available"; return 2
+if [[ $(whence git >/dev/null) || false ]]; then
+else
+  echo "git is not available"
+  return 2
+fi
 
-if mkdir "$_DOTFILES/log/update.lock" 2>/dev/null; then
-  if [ -f ~/.dotfiles-update ]; then
-    . ~/.dotfiles-update
+if mkdir -p "$_DOTFILES/update.lock" 2>/dev/null; then
+  if [ -f ${HOME}/.dotfiles-update ]; then
+    . ${HOME}/.dotfiles-update
 
     if [[ -z "$LAST_EPOCH" ]]; then
-      _update_zsh_update && return 0;
+      echo "Missing \$LAST_EPOCH"
+      _update_dotfiles_update && return 0;
     fi
 
     epoch_diff=$(($(_current_epoch) - $LAST_EPOCH))
@@ -53,9 +63,10 @@ if mkdir "$_DOTFILES/log/update.lock" 2>/dev/null; then
       fi
     fi
   else
+    echo "Missing ~/.dotfiles-update"
     # create the zsh file
     _update_dotfiles_update
   fi
 
-  rmdir $_DOTFILES/log/update.lock
+  rmdir $_DOTFILES/update.lock
 fi
diff --git a/shell/env b/shell/env
index c75860b..c92fe1a 100644
--- a/shell/env
+++ b/shell/env
@@ -15,6 +15,9 @@ export _DOTFILES="${HOME}/dotfiles"
 # Allow automatic updates
 export DISABLE_DOTFILES_AUTO_UPDATE="FALSE"
 
+# Set "true" to update without asking first
+export DISABLE_DOTFILES_UPDATE_PROMPT="FALSE"
+
 # Update every 2 weeks (OMZ default)
 export UPDATE_DOTFILES_DAYS=13
 
diff --git a/shell/zshrc b/shell/zshrc
index 4e10408..80f9d2b 100644
--- a/shell/zshrc
+++ b/shell/zshrc
@@ -42,7 +42,7 @@ bindkey "^[s" insert-sudo
 # Check for updates...
 # Stolen and modified Oh-My-ZSH's update system
 if [ "$DISABLE_DOTFILES_AUTO_UPDATE" != "true" ]; then
-  env ZSH=$ZSH DOTFILES=$DOTFILES DISABLE_UPDATE_PROMPT=$DISABLE_UPDATE_PROMPT zsh -f $DOTFILES/check_for_upgrade.sh
+  env ZSH=$ZSH _DOTFILES=$_DOTFILES DISABLE_UPDATE_PROMPT=$DISABLE_DOTFILES_UPDATE_PROMPT zsh -f $_DOTFILES/check_for_upgrade.sh
 fi
 
 # Oh-My-ZSH Options below this line