diff --git a/src/io/io.f90 b/src/io/io.f90
index 85a8d42b3..b0a752863 100644
--- a/src/io/io.f90
+++ b/src/io/io.f90
@@ -270,7 +270,7 @@ module subroutine io_dump_system(self, param)
    end subroutine io_dump_system
 
 
-   module subroutine io_dump_storage(self, param, system)
+   module subroutine io_dump_storage(self, param)
       !! author: David A. Minton
       !!
       !! Dumps the time history of the simulation to file. Each time it writes a frame to file, it deallocates the system
@@ -281,7 +281,6 @@ module subroutine io_dump_storage(self, param, system)
       ! Arguments
       class(swiftest_storage(*)),   intent(inout)        :: self   !! Swiftest simulation history storage object
       class(swiftest_parameters),   intent(inout)        :: param  !! Current run configuration parameters 
-      class(swiftest_nbody_system), intent(in), optional :: system !! Swiftest nbody system object (Note, only here so that it can be used in the extended type for encounter_storage)
       ! Internals
       integer(I4B) :: i
       integer(I8B) :: iloop_start
diff --git a/src/modules/swiftest_classes.f90 b/src/modules/swiftest_classes.f90
index fa0bdf865..8ddaf0c65 100644
--- a/src/modules/swiftest_classes.f90
+++ b/src/modules/swiftest_classes.f90
@@ -632,11 +632,10 @@ module subroutine io_dump_system(self, param)
          class(swiftest_parameters),    intent(inout) :: param  !! Current run configuration parameters 
       end subroutine io_dump_system
 
-      module subroutine io_dump_storage(self, param, system)
+      module subroutine io_dump_storage(self, param)
          implicit none
          class(swiftest_storage(*)),   intent(inout)        :: self   !! Swiftest simulation history storage object
          class(swiftest_parameters),   intent(inout)        :: param  !! Current run configuration parameters 
-         class(swiftest_nbody_system), intent(in), optional :: system !! Swiftest nbody system object
       end subroutine io_dump_storage
 
       module subroutine io_get_args(integrator, param_file_name, display_style)