diff --git a/src/netcdf/netcdf.f90 b/src/netcdf/netcdf.f90
index ab05d3c2a..384a7f437 100644
--- a/src/netcdf/netcdf.f90
+++ b/src/netcdf/netcdf.f90
@@ -677,6 +677,7 @@ module subroutine netcdf_read_particle_info_system(self, iu, plmask, tpmask)
             do i = 1, ntp
                call tp%info(i)%set_value(status="ACTIVE")
             end do
+            allocate(tpind(ntp))
             tpind(:) = pack([(i, i = 1, idmax)], tpmask(:))
          end if