diff --git a/src/nmt_io.c b/src/nmt_io.c
index 5b49a50..bb53372 100644
--- a/src/nmt_io.c
+++ b/src/nmt_io.c
@@ -17,6 +17,7 @@ static void nmt_workspace_info_tohdus(fitsfile *fptr,
   fits_write_key(fptr,TINT,"LMAX_MASK",&(w->lmax_mask),NULL,status);
   fits_write_key(fptr,TINT,"IS_TEB",&(w->is_teb),NULL,status);
   fits_write_key(fptr,TINT,"NCLS",&(w->ncls),NULL,status);
+  fits_write_key(fptr,TINT,"NORM_TYPE",&(w->norm_type),NULL,status);
   for(ii=0;ii<n_el;ii++) {
     fpixel[1]=ii+1;
     fits_write_pix(fptr,TDOUBLE,fpixel,n_el,w->coupling_matrix_unbinned[ii],status);
@@ -28,12 +29,19 @@ static void nmt_workspace_info_fromhdus(fitsfile *fptr,
 					int w_unbinned,
 					int *status)
 {
+  int status_pre;
   fits_movnam_hdu(fptr,IMAGE_HDU,"WSP_PRIMARY",0,status);
   fits_read_key(fptr,TINT,"LMAX",&(w->lmax),NULL,status);
   fits_read_key(fptr,TINT,"LMAX_FIELDS",&(w->lmax_fields),NULL,status);
   fits_read_key(fptr,TINT,"LMAX_MASK",&(w->lmax_mask),NULL,status);
   fits_read_key(fptr,TINT,"IS_TEB",&(w->is_teb),NULL,status);
   fits_read_key(fptr,TINT,"NCLS",&(w->ncls),NULL,status);
+  status_pre = *status;
+  fits_read_key(fptr,TINT,"NORM_TYPE",&(w->norm_type),NULL,status);
+  if(*status) {// maybe used old format
+    w->norm_type=0;
+    *status=status_pre;
+  }
   long ii;
   long n_el=w->ncls*(w->lmax+1);
   long fpixel[2]={1,1};