diff --git a/var/spack/repos/builtin/packages/r-fit-models/package.py b/var/spack/repos/builtin/packages/r-fit-models/package.py
index 6fcbe77551..ae80f1946e 100644
--- a/var/spack/repos/builtin/packages/r-fit-models/package.py
+++ b/var/spack/repos/builtin/packages/r-fit-models/package.py
@@ -7,12 +7,23 @@
 
 
 class RFitModels(RPackage):
-    """Compare Fitted Models"""
+    """Compare Fitted Models
+
+    The fit.models function and its associated methods (coefficients, print,
+    summary, plot, etc.) were originally provided in the robust package to
+    compare robustly and classically fitted model objects. See chapters 2, 3,
+    and 5 in Insightful (2002) 'Robust Library User's Guide'
+    <http://robust.r-forge.r-project.org/Robust.pdf>). The aim of the
+    fit.models package is to separate this fitted model object comparison
+    functionality from the robust package and to extend it to support fitting
+    methods (e.g., classical, robust, Bayesian, regularized, etc.) more
+    generally."""
 
     homepage = "https://cloud.r-project.org/package=fit.models"
     url      = "https://cloud.r-project.org/src/contrib/fit.models_0.5-14.tar.gz"
     list_url = "https://cloud.r-project.org/src/contrib/Archive/fit.models"
 
+    version('0.64', sha256='f70806bfa85a05337fa5a665264d640e307584714a07a329fbe96c86b0e864da')
     version('0.5-14', sha256='93b9d119e97b36c648a19c891fc5e69f5306eb5b9bac16bf377555057afd4b6e')
     version('0.5-13', sha256='7df545fce135159e9abf0a19076628d3ec2999e89f018e142a7a970428823d48')