diff --git a/src/epub/onix.xml b/src/epub/onix.xml
index cabf4e3..c44bda7 100644
--- a/src/epub/onix.xml
+++ b/src/epub/onix.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<ONIXMessage xmlns="http://ns.editeur.org/onix/3.0/reference" release="3.0">
+<ONIXMessage xmlns="http://ns.editeur.org/onix/3.1/reference" release="3.1">
 	<Header>
 		<Sender>
 			<SenderName>Standard Ebooks</SenderName>
@@ -8,6 +8,11 @@
 	</Header>
 	<Product>
 		<DescriptiveDetail>
+			<ProductFormFeature>
+				<!--Compliant with ePub Accessibility Spec v1.1-->
+				<ProductFormFeatureType>09</ProductFormFeatureType>
+				<ProductFormFeatureValue>04</ProductFormFeatureValue>
+			</ProductFormFeature>
 			<ProductFormFeature>
 				<!--No reading system accessibility options disabled-->
 				<ProductFormFeatureType>09</ProductFormFeatureType>
@@ -33,6 +38,33 @@
 				<ProductFormFeatureType>09</ProductFormFeatureType>
 				<ProductFormFeatureValue>22</ProductFormFeatureValue>
 			</ProductFormFeature>
+			<ProductFormFeature>
+				<!--All non-decorative content supports reading without sight-->
+				<ProductFormFeatureType>09</ProductFormFeatureType>
+				<ProductFormFeatureValue>52</ProductFormFeatureValue>
+			</ProductFormFeature>
+			<ProductFormFeature>
+				<!--WCAG v2.2-->
+				<ProductFormFeatureType>09</ProductFormFeatureType>
+				<ProductFormFeatureValue>82</ProductFormFeatureValue>
+			</ProductFormFeature>
+			<ProductFormFeature>
+				<!--WCAG level AA-->
+				<ProductFormFeatureType>09</ProductFormFeatureType>
+				<ProductFormFeatureValue>85</ProductFormFeatureValue>
+			</ProductFormFeature>
+			<ProductFormFeature>
+				<!--Publisher’s web page for detailed accessibility information-->
+				<ProductFormFeatureType>09</ProductFormFeatureType>
+				<ProductFormFeatureValue>96</ProductFormFeatureValue>
+				<ProductFormFeatureDescription>https://standardebooks.org/about/accessibility</ProductFormFeatureDescription>
+			</ProductFormFeature>
+			<ProductFormFeature>
+				<!--Publisher contact for further accessibility information-->
+				<ProductFormFeatureType>09</ProductFormFeatureType>
+				<ProductFormFeatureValue>99</ProductFormFeatureValue>
+				<ProductFormFeatureDescription>standardebooks@googlegroups.com</ProductFormFeatureDescription>
+			</ProductFormFeature>
 		</DescriptiveDetail>
 	</Product>
 </ONIXMessage>