diff --git a/VERSION b/VERSION
index 9cec716..23887f6 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.1.6
+3.1.7
diff --git a/lib/rdf/vocab.rb b/lib/rdf/vocab.rb
index 208a8de..f6de911 100644
--- a/lib/rdf/vocab.rb
+++ b/lib/rdf/vocab.rb
@@ -248,7 +248,7 @@ module Vocab
               rdfs:comment "A description of what is in the image (not a caption). If the page specifies an og:image it should specify og:image:alt."@en-US ;
               rdfs:seeAlso og:image ;
               rdfs:isDefinedBy og: ;
-              rdfs:range ogc:url .
+              rdfs:range ogc:string .
             og:locale:alternate a rdf:Property ;
               rdfs:label "locale:alternate"@en-US ;
               rdfs:comment "An array of other locales this page is available in."@en-US ;
diff --git a/lib/rdf/vocab/og.rb b/lib/rdf/vocab/og.rb
index 2e34b71..eaa3dda 100644
--- a/lib/rdf/vocab/og.rb
+++ b/lib/rdf/vocab/og.rb
@@ -162,7 +162,7 @@ module RDF::Vocab
       comment: %(A description of what is in the image \(not a caption\). If the page specifies an og:image it should specify og:image:alt.).freeze,
       isDefinedBy: "og:".freeze,
       label: "image:alt".freeze,
-      range: "ogc:url".freeze,
+      range: "ogc:string".freeze,
       "rdfs:seeAlso": "og:image".freeze,
       type: "rdf:Property".freeze
     property :"image:height",