diff --git a/shopping-item-cqre-and-es/pom.xml b/shopping-item-cqre-and-es/pom.xml
index 1a7e314..b782e46 100644
--- a/shopping-item-cqre-and-es/pom.xml
+++ b/shopping-item-cqre-and-es/pom.xml
@@ -78,7 +78,7 @@
     <dependency> <!-- use a specific Groovy version rather than the one specified by spock-core -->
       <groupId>org.codehaus.groovy</groupId>
       <artifactId>groovy-all</artifactId>
-      <version>2.4.13</version>
+      <version>2.4.21</version>
     </dependency>
     <dependency> <!-- enables mocking of classes (in addition to interfaces) -->
       <groupId>net.bytebuddy</groupId>