diff --git a/build.xml b/build.xml
index 264203454e..2cb637e555 100644
--- a/build.xml
+++ b/build.xml
@@ -1106,7 +1106,7 @@
         <formatter type="brief" usefile="false"/>
         <jvmarg value="-Dstorage-config=${test.conf}"/>
         <jvmarg value="-Djava.awt.headless=true"/>
-        <jvmarg value="-javaagent:${basedir}/lib/jamm-0.2.8.jar ${additionalagent}" />
+        <jvmarg line="-javaagent:${basedir}/lib/jamm-0.2.8.jar ${additionalagent}" />
         <jvmarg value="-ea"/>
         <jvmarg value="-Xss256k"/>
         <jvmarg value="-Dcassandra.memtable_row_overhead_computation_step=100"/>