diff --git a/build.xml b/build.xml
index fedcabd..a6956c8 100644
--- a/build.xml
+++ b/build.xml
@@ -28,13 +28,13 @@
       <dependency
         groupId="org.spockframework"
         artifactId="spock-core"
-        version="1.1-groovy-2.4-rc-3" />
+        version="1.1-groovy-2.4" />
 <!-- Optional dependencies for using Spock -->
       <!-- enables mocking of classes (in addition to interfaces) -->
       <dependency
-        groupId="cglib"
-        artifactId="cglib-nodep"
-        version="3.2.4" />
+        groupId="net.bytebuddy"
+        artifactId="byte-buddy"
+        version="1.6.5" />
       <!-- enables mocking of classes without parameterless constructor (together with CGLIB) -->
       <dependency
         groupId="org.objenesis"