diff --git a/public/biopet-tools-extensions/src/main/scala/nl/lumc/sasc/biopet/extensions/tools/GensToVcf.scala b/public/biopet-tools-extensions/src/main/scala/nl/lumc/sasc/biopet/extensions/tools/GensToVcf.scala
index 2208d0bbffaba853a584df910042ea6216a976cd..c620bc161caefc962e0b1687e3222c39fdcd6e62 100644
--- a/public/biopet-tools-extensions/src/main/scala/nl/lumc/sasc/biopet/extensions/tools/GensToVcf.scala
+++ b/public/biopet-tools-extensions/src/main/scala/nl/lumc/sasc/biopet/extensions/tools/GensToVcf.scala
@@ -45,6 +45,8 @@ class GensToVcf(val root: Configurable) extends ToolCommandFunction with Referen
 
   var contig: String = _
 
+  override def defaultCoreMemory = 5.0
+
   override def beforeGraph(): Unit = {
     super.beforeGraph()
     if (reference == null) reference = referenceFasta()