diff --git a/README.md b/README.md
index 014921486ee..1293fbefd03 100644
--- a/README.md
+++ b/README.md
@@ -107,7 +107,7 @@ sudo zypper install libX11-devel libexpat-devel libbz2-devel Mesa-libEGL-devel M
 #### On Arch Linux
 
 ``` sh
-sudo pacman -S --needed base-devel git python2 python2-virtualenv python2-pip mesa cmake bzip2 libxmu glu pkg-config
+sudo pacman -S --needed base-devel git python2 python2-virtualenv python2-pip mesa cmake bzip2 libxmu glu pkg-config clang
 ```
 #### On Gentoo Linux
 
@@ -138,9 +138,9 @@ list of installed components. It is not on by default. Visual Studio 2017 MUST i
 > If you encountered errors with the environment above, do the following for a workaround:
 > 1.  Download and install [Build Tools for Visual Studio 2017](https://www.visualstudio.com/thank-you-downloading-visual-studio/?sku=BuildTools&rel=15)
 > 2.  Install `python2.7 x86-x64` and `virtualenv`
-> 3.  Run `mach.bat build -d`. 
+> 3.  Run `mach.bat build -d`.
 
->If you have troubles with `x64 type` prompt as `mach.bat` set by default:  
+>If you have troubles with `x64 type` prompt as `mach.bat` set by default:
 > 1. you may need to choose and launch the type manually, such as `x86_x64 Cross Tools Command Prompt for VS 2017` in the Windows menu.)
 > 2. `cd to/the/path/servo`
 > 3. `python mach build -d`