diff --git a/conf/base.config b/conf/base.config
index 20c3481c..98a57035 100644
--- a/conf/base.config
+++ b/conf/base.config
@@ -36,7 +36,7 @@ process {
       time   = {  if (task.attempt == 1) { check_max( 16.h * task.attempt, 'time' ) } else { params.max_time } }
       
       // retry at least once to try it with full resources
-      errorStrategy = { task.exitStatus in [143,137,104,134,139] ? 'retry' : 'finish' }
+      errorStrategy = { task.exitStatus in [21,143,137,104,134,139] ? 'retry' : 'finish' }
       maxRetries    = 1
       maxErrors     = '-1'
     }