diff --git a/docs/changelog.rst b/docs/changelog.rst
index 7f56dae..c30423a 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -4,6 +4,11 @@ Changelog
 v0.0.3
 ------
 
+New Features
+~~~~~~~~~~~~
+
+- The :code:`gamma` parameter was added to :code:`defaultParameters` and :code:`describeParameters`.
+
 Improvements
 ~~~~~~~~~~~~
 
diff --git a/spectral/spectral.js b/spectral/spectral.js
index 643482f..e79e0e3 100755
--- a/spectral/spectral.js
+++ b/spectral/spectral.js
@@ -82,6 +82,7 @@ var defaultParameters = {
   "cexp": 1.16,
   "nexp": 2.0,
   "alpha": 0.1,
+  "gamma": 1.0,
   "sla": 1.0,
   "slb": 0.0,
   "p": 2.0,
@@ -116,6 +117,7 @@ var describeParameters = {
       "cexp": "Exponent used for OCVI",
       "nexp": "Exponent used for GDVI",
       "alpha": "Weighting coefficient used for WDRVI",
+      "gamma": "Weighting coefficient used for ARVI",
       "sla": "Soil line slope",
       "slb": "Soil line intercept"
     },