diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index ac8528a..b441336 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -14,7 +14,7 @@
 
 # xosproject/simpleexampleservice-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.1.9
+FROM xosproject/xos-synchronizer-base:2.1.21
 
 COPY xos/synchronizer /opt/xos/synchronizers/simpleexampleservice
 COPY VERSION /opt/xos/synchronizers/simpleexampleservice/