diff --git a/src/collision/collision_util.f90 b/src/collision/collision_util.f90
index 35d4e10f2..fb0cbee06 100644
--- a/src/collision/collision_util.f90
+++ b/src/collision/collision_util.f90
@@ -88,6 +88,10 @@ module subroutine collision_util_construct_temporary_system(self, nbody_system,
             if (allocated(tmpparam)) deallocate(tmpparam)
             if (allocated(tmpsys)) deallocate(tmpsys)
             allocate(tmpparam_local, source=param)
+            select type(tmpparam_local)
+            class is (swiftest_parameters)
+               tmpparam_local%system_history%nc%lfile_is_open = .false.
+            end select
             call swiftest_util_setup_construct_system(tmpsys_local, tmpparam_local)
 
             ! No test particles necessary for energy/momentum calcs
diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index de81b75bc..276024b3f 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -125,6 +125,10 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       ! end if
 
       allocate(tmp_param, source=param)
+      select type(tmp_param)
+      class is (swiftest_parameters)
+         tmp_param%system_history%nc%lfile_is_open = .false.
+      end select
 
       ! Turn off adaptive encounter checks for the pl-pl group
       tmp_param%ladaptive_encounters_plpl = .false.