diff --git a/bwa.wdl b/bwa.wdl
index 2d9502efc25d1aaa23c5d04b3299edb83894c4ef..e97ae481fc592b2ecdfb91c9f53049de32d7530f 100644
--- a/bwa.wdl
+++ b/bwa.wdl
@@ -1,4 +1,4 @@
-task BwaMem {
+task mem {
     String? preCommand
     File inputR1
     File? inputR2
@@ -10,6 +10,7 @@ task BwaMem {
     Int? threads
     Int? memory
 
+
     command {
         set -e -o pipefail
         mkdir -p $(dirname ${outputPath})
@@ -23,8 +24,8 @@ task BwaMem {
         File bamFile = outputPath
     }
     runtime{
-        cpu: if defined(threads) then threads else 1
-        memory: if defined(memory) then memory else 8
+        cpu: select_first([threads,1])
+        memory: select_first([memory,8])
     }
 }