diff --git a/ondex-opt/modules-opt/expression/pom.xml b/ondex-opt/modules-opt/expression/pom.xml
index ee5edd8..75a0d72 100644
--- a/ondex-opt/modules-opt/expression/pom.xml
+++ b/ondex-opt/modules-opt/expression/pom.xml
@@ -49,7 +49,7 @@
       <dependency>
          <groupId>com.thoughtworks.xstream</groupId>
          <artifactId>xstream</artifactId>
-         <version>1.3.1</version>
+         <version>1.4.17</version>
          <type>jar</type>
          <scope>test</scope>
       </dependency>