diff --git a/README.rst b/README.rst
index 1761d3398c24a6a47e988ea4026bf1b7feab693b..3d2a8ae348abfe65c5a53b16428bf8ae9c0ce83b 100644
--- a/README.rst
+++ b/README.rst
@@ -115,8 +115,8 @@ Installing prerequisites on CentOS 7::
 
     sudo yum install libtiff-devel libjpeg-devel libzip-devel freetype-devel \
                      lcms2-devel libwebp-devel tcl-devel tk-devel \
-                     python-virtualenv
-                     sudo yum groupinstall "Development Tools"
+                     python-virtualenv libffi-devel
+    sudo yum groupinstall "Development Tools"
 
 
 Installing prerequisites on Mac OS X::