diff --git a/bwa.wdl b/bwa.wdl
index 665b63ca34501999b89e05e3864ace61754fbbd7..4025610130db3b8d2f0a3bc7b01a44ed26bc7dae 100644
--- a/bwa.wdl
+++ b/bwa.wdl
@@ -28,7 +28,7 @@ task Mem {
         String outputPath
         String? readgroup
 
-        Int threads = 2
+        Int threads = 4
         String memory = "32G"
         String picardXmx = "4G"
         # A mulled container is needed to have both picard and bwa in one container.