diff --git a/src/swiftest/swiftest_io.f90 b/src/swiftest/swiftest_io.f90
index 21b52b714..d88402be2 100644
--- a/src/swiftest/swiftest_io.f90
+++ b/src/swiftest/swiftest_io.f90
@@ -2769,7 +2769,11 @@ module subroutine swiftest_io_set_display_param(self, display_style)
          self%display_unit = OUTPUT_UNIT !! stdout from iso_fortran_env
          self%log_output = .false.
       case ('COMPACT', 'PROGRESS')
-         open(unit=SWIFTEST_LOG_OUT, file=SWIFTEST_LOG_FILE, status=self%out_stat, err = 667, iomsg = errmsg)
+         if (self%lrestart) then
+            open(unit=SWIFTEST_LOG_OUT, file=SWIFTEST_LOG_FILE, status="OLD", position="APPEND", err = 667, iomsg = errmsg)
+         else
+            open(unit=SWIFTEST_LOG_OUT, file=SWIFTEST_LOG_FILE, status="REPLACE", err = 667, iomsg = errmsg)
+         end if
          self%display_unit = SWIFTEST_LOG_OUT 
          self%log_output = .true.
       case default