diff --git a/src/plaza/rdf/implementations/common.clj b/src/plaza/rdf/implementations/common.clj
index 99bf860..166f997 100644
--- a/src/plaza/rdf/implementations/common.clj
+++ b/src/plaza/rdf/implementations/common.clj
@@ -46,6 +46,7 @@
         (= "float" (.toLowerCase (keyword-to-string lit))) XSDDatatype/XSDfloat
         (= "int" (.toLowerCase (keyword-to-string lit))) XSDDatatype/XSDint
         (= "integer" (.toLowerCase (keyword-to-string lit))) XSDDatatype/XSDinteger
+        (= "nonnegativeinteger" (.toLowerCase (keyword-to-string lit))) XSDDatatype/XSDnonNegativeInteger
         (= "long" (.toLowerCase (keyword-to-string lit))) XSDDatatype/XSDlong
         (= "string" (.toLowerCase (keyword-to-string lit))) XSDDatatype/XSDstring
         :else (make-custom-type literal)))))
@@ -70,6 +71,7 @@
          "float" (keyword lit)
          "int" (keyword lit)
          "integer" (keyword lit)
+         "nonNegativeInteger" (keyword lit)
          "long" (keyword lit)
          "string" (keyword lit)
          nil))))
diff --git a/src/plaza/rdf/implementations/sesame.clj b/src/plaza/rdf/implementations/sesame.clj
index 5aa18bd..13b348d 100644
--- a/src/plaza/rdf/implementations/sesame.clj
+++ b/src/plaza/rdf/implementations/sesame.clj
@@ -43,6 +43,7 @@
         (= "float" (.toLowerCase (keyword-to-string lit))) "http://www.w3.org/2001/XMLSchema#float"
         (= "int" (.toLowerCase (keyword-to-string lit))) "http://www.w3.org/2001/XMLSchema#int"
         (= "integer" (.toLowerCase (keyword-to-string lit))) "http://www.w3.org/2001/XMLSchema#integer"
+        (= "nonnegativeinteger" (.toLowerCase (keyword-to-string lit))) "http://www.w3.org/2001/XMLSchema#nonNegativeInteger"
         (= "long" (.toLowerCase (keyword-to-string lit))) "http://www.w3.org/2001/XMLSchema#long"
         (= "string" (.toLowerCase (keyword-to-string lit))) "http://www.w3.org/2001/XMLSchema#string"
         :else literal))))
@@ -61,6 +62,7 @@
       (= "http://www.w3.org/2001/XMLSchema#float" (str (.getDatatype lit))) (.floatValue lit)
       (= "http://www.w3.org/2001/XMLSchema#int" (str (.getDatatype lit))) (.intValue lit)
       (= "http://www.w3.org/2001/XMLSchema#integer" (str (.getDatatype lit))) (.integerValue lit)
+      (= "http://www.w3.org/2001/XMLSchema#nonNegativeInteger" (str (.getDatatype lit))) (.integerValue lit)
       (= "http://www.w3.org/2001/XMLSchema#long" (str (.getDatatype lit))) (.longValue lit)
       (= "http://www.w3.org/2001/XMLSchema#string" (str (.getDatatype lit))) (.stringValue lit)
       true (.stringValue lit))))