diff --git a/pom.xml b/pom.xml
index 74f7df0..da2c602 100644
--- a/pom.xml
+++ b/pom.xml
@@ -167,7 +167,7 @@
         <dependency>
             <groupId>com.thoughtworks.xstream</groupId>
             <artifactId>xstream</artifactId>
-            <version>1.4.7</version>
+            <version>1.4.19</version>
         </dependency>
         <dependency>
             <groupId>com.google.code.gson</groupId>
diff --git a/src/main/java/org/sputnikdev/bluetooth/gattparser/spec/BluetoothGattSpecificationReader.java b/src/main/java/org/sputnikdev/bluetooth/gattparser/spec/BluetoothGattSpecificationReader.java
index e916fbc..3491ff5 100644
--- a/src/main/java/org/sputnikdev/bluetooth/gattparser/spec/BluetoothGattSpecificationReader.java
+++ b/src/main/java/org/sputnikdev/bluetooth/gattparser/spec/BluetoothGattSpecificationReader.java
@@ -29,12 +29,10 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.File;
-import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.lang.reflect.Type;
 import java.net.MalformedURLException;
-import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -44,7 +42,6 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Scanner;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -397,6 +394,8 @@ private Characteristic getCharacteristic(URL file) {
     private <T> T getSpec(URL file) {
         try {
             XStream xstream = new XStream(new DomDriver());
+            xstream.allowTypesByWildcard(
+                    new String[]{getClass().getPackage().getName() + ".*"});
             xstream.autodetectAnnotations(true);
             xstream.processAnnotations(Bit.class);
             xstream.processAnnotations(BitField.class);