diff --git a/build-monitor-acceptance/pom.xml b/build-monitor-acceptance/pom.xml
index 96b3b653..ac9bb797 100644
--- a/build-monitor-acceptance/pom.xml
+++ b/build-monitor-acceptance/pom.xml
@@ -52,7 +52,7 @@
       <dependency>
         <groupId>com.thoughtworks.xstream</groupId>
         <artifactId>xstream</artifactId>
-        <version>1.4.20</version>
+        <version>1.4.21</version>
       </dependency>
       <dependency>
         <groupId>commons-codec</groupId>