diff --git a/content-rdf/src/main/java/org/xbib/content/rdf/internal/DefaultLiteral.java b/content-rdf/src/main/java/org/xbib/content/rdf/internal/DefaultLiteral.java
index 3a6f1a9..ecfc726 100644
--- a/content-rdf/src/main/java/org/xbib/content/rdf/internal/DefaultLiteral.java
+++ b/content-rdf/src/main/java/org/xbib/content/rdf/internal/DefaultLiteral.java
@@ -94,20 +94,25 @@ public class DefaultLiteral implements Literal, Comparable<Literal> {
             return value;
         }
         String s = value.toString();
-        switch (type.toString()) {
-            case "xsd:long":
-                return Long.parseLong(s);
-            case "xsd:int":
-            case "xsd:gYear":
-                return Integer.parseInt(s);
-            case "xsd:boolean":
-                return Boolean.parseBoolean(s);
-            case "xsd:float":
-                return Float.parseFloat(s);
-            case "xsd:double":
-                return Double.parseDouble(s);
-            default:
-                return s;
+        try {
+            switch (type.toString()) {
+                case "xsd:long":
+                    return Long.parseLong(s);
+                case "xsd:int":
+                    return Integer.parseInt(s);
+                case "xsd:gYear":
+                    return Integer.parseInt(s);
+                case "xsd:boolean":
+                    return Boolean.parseBoolean(s);
+                case "xsd:float":
+                    return Float.parseFloat(s);
+                case "xsd:double":
+                    return Double.parseDouble(s);
+                default:
+                    return s;
+            }
+        } catch (NumberFormatException e) {
+            return null;
         }
     }
 
diff --git a/gradle.properties b/gradle.properties
index c257dc8..dc55aa0 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,6 +1,6 @@
 group = org.xbib
 name = content
-version = 1.2.1
+version = 1.2.2
 
 jackson.version = 2.8.11
 xbib-net.version = 1.0.0