diff --git a/docs/source/usersguide/install.rst b/docs/source/usersguide/install.rst
index 971c3bb01..bff9f8d1f 100644
--- a/docs/source/usersguide/install.rst
+++ b/docs/source/usersguide/install.rst
@@ -11,7 +11,7 @@ Prerequisites
 In order to compile OpenMC, you will need to have a Fortran compiler installed
 on your machine. Since a number of Fortran 2003/2008 features are used in the
 code, it is recommended that you use the latest version of whatever compiler you
-choose. For gfortran_, it is recommended that you use version 4.5.0 or above.
+choose. For gfortran_, it is necessary to use version 4.6.0 or above.
 
 If you are using Debian or a Debian derivative such as Ubuntu, you can install
 the gfortran compiler using the following command::