diff --git a/README.md b/README.md
index 136704c..b94aff5 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,18 @@ An attempt at providing [Fish shell](http://www.fishshell.org) like syntax highl
 
 ## Usage
 
-Just source the script from your `~/.zshrc`.
+Download the script or clone this repository:
+
+    git clone git://github.com/nicoulaj/zsh-syntax-highlighting.git
+
+Update your `~/.zshrc` so that the script is sourced:
+
+    source /path/to/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh
+
+Re-open your terminal, or just reload it to take changes into account:
+
+    source ~/.zshrc
+
 
 ## References
 
@@ -21,3 +32,4 @@ Just source the script from your `~/.zshrc`.
  * [Jonathan Dahan](http://github.com/jedahan)
  * James Ahlborn
  * [Andreas Jaggi](http://github.com/x-way)
+ * [Wayne Davison](http://github.com/WayneD)
diff --git a/zsh-syntax-highlighting.zsh b/zsh-syntax-highlighting.zsh
index 882b847..ba298be 100644
--- a/zsh-syntax-highlighting.zsh
+++ b/zsh-syntax-highlighting.zsh
@@ -61,7 +61,7 @@ colorize-zle-buffer() {
 	esac
     fi
     region_highlight+=("$start_pos $end_pos $style")
-    [[ ${${ZLE_TOKENS_FOLLOWED_BY_COMMANDS[(r)${arg//|/\|}]}:+yes} = 'yes' ]] && colorize=true
+    [[ ${${ZLE_TOKENS_FOLLOWED_BY_COMMANDS[(r)${arg//|/\|}]:-}:+yes} = 'yes' ]] && colorize=true
     start_pos=$end_pos
   done
 }