diff --git a/src/global.F90 b/src/global.F90
index 4c42183139..e7518079a9 100644
--- a/src/global.F90
+++ b/src/global.F90
@@ -292,6 +292,9 @@ module global
   ! Particle restart run
   logical :: particle_restart_run = .false.
 
+  ! Write out initial source
+  logical :: write_initial_source = .false.
+
   ! ============================================================================
   ! CMFD VARIABLES 
 
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index f8db7f3235..a569222d13 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -255,6 +255,14 @@ contains
       call fatal_error()
     end if
 
+    ! Check if we want to write out source
+    if (check_for_node(node_source, "write_initial")) then
+      call get_node_value(node_source, "write_initial", temp_str)
+      call lower_case(temp_str)
+      if (trim(temp_str) == 'true' .or. trim(temp_str) == '1') &
+           write_initial_source = .true.
+    end if
+
     ! Check for external source file
     if (check_for_node(node_source, "file")) then
       ! Copy path of source file
diff --git a/src/source.F90 b/src/source.F90
index dd7777fdb7..63f9ee495f 100644
--- a/src/source.F90
+++ b/src/source.F90
@@ -27,6 +27,7 @@ contains
 
   subroutine initialize_source()
 
+    character(MAX_FILE_LEN) :: filename
     integer(8) :: i          ! loop index over bank sites
     integer(8) :: id         ! particle id
     integer(4) :: itmp       ! temporary integer
@@ -70,6 +71,16 @@ contains
       end do
     end if
 
+    ! Write out initial source
+    if (write_initial_source) then
+      message = 'Writing out initial source guess...'
+      call write_message(1)
+      filename = 'initial_source.h5'
+      call sp % file_create(filename, serial = .false.)
+      call sp % write_source_bank()
+      call sp % file_close()
+    end if
+
   end subroutine initialize_source
 
 !===============================================================================