diff --git a/gridss.wdl b/gridss.wdl
index 3b7859b653f93f8160ac5c79023d0480dd943f09..3649cb1becd3159b5fcf0ecdb08edf19bf305ec7 100644
--- a/gridss.wdl
+++ b/gridss.wdl
@@ -78,6 +78,7 @@ task GRIDSS {
         outputPrefix: {description: "The prefix for the output files. This may include parent directories.", category: "common"}
 
         threads: {description: "The number of the threads to use.", category: "advanced"}
+        javaXmxMb: {description: "The size of JVM heap for assembly and variant calling",category: "advanced"}
         dockerImage: {description: "The docker image used for this task. Changing this may result in errors which the developers may choose not to address.", category: "advanced"}
     }
 }
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