diff --git a/src/global.F90 b/src/global.F90
index 12c88fc584..33dd9b7594 100644
--- a/src/global.F90
+++ b/src/global.F90
@@ -166,7 +166,7 @@ module global
   integer(8) :: bank_last    ! index of last particle in bank
   integer(8) :: work         ! number of particles per processor
   integer(8) :: maxwork      ! maximum number of particles per processor
-  integer(8) :: current_work ! current work
+  integer(8) :: current_work ! index in source bank of current history simulated
 
   ! Temporary k-effective values
   real(8), allocatable :: k_batch(:) ! batch estimates of k