diff --git a/src/model.f90 b/src/model.f90
index 0b2fbb4..0fedcc6 100644
--- a/src/model.f90
+++ b/src/model.f90
@@ -324,6 +324,10 @@ subroutine write_model(this, subname)
       call h%add('/lat',this%ygrids)
       call h%add('/dep',this%zgrids)
       call h%add('/vs',transpose_3(this%vs3d))
+      if (ap%inversion%use_alpha_beta_rho) then
+        call h%add('/vp',transpose_3(this%vp3d))
+        call h%add('/rho',transpose_3(this%rho3d))
+      endif
       call h%close()
     endif
     call synchronize_all()