diff --git a/jass/models/inittable.py b/jass/models/inittable.py
index c568c8eef2dc7370d76f64d9f572e8647362a92e..719a92680e6ab8c86e7d7916d634b543c205728c 100755
--- a/jass/models/inittable.py
+++ b/jass/models/inittable.py
@@ -222,7 +222,7 @@ def create_inittable_file(
     which_cols.extend(list(pheno_select))
     hdf_init.put("PhenoList", pheno_list, format="table", data_columns=True)
     hdf_init.put("Regions", regions, format="table", data_columns=True)
-    sum_stat_tab_min_itemsizes = {"snp_ids": 50, "Ref_allele":50,"Alt_allele":50}
+    sum_stat_tab_min_itemsizes = {"snp_ids": 80, "Ref_allele":70,"Alt_allele":70}
 
     regions_bychr = regions.groupby("chr")
 
diff --git a/jass/models/worktable.py b/jass/models/worktable.py
index c2e287a530f4ca5c03a892c470d8ada28c3a61d7..a249eb9bc8cd3f765d440d7bdda7587fbcb18aa4 100755
--- a/jass/models/worktable.py
+++ b/jass/models/worktable.py
@@ -193,9 +193,9 @@ def create_worktable_file(
     )  # Covariance matrix
 
     regions = read_hdf(init_file_path, "Regions").index.tolist()
-    sum_stat_tab_min_itemsizes = {"snp_ids": 50, "Region": 10, "CHR": 5,"Ref_allele" : 50, "Alt_allele":50}
+    sum_stat_tab_min_itemsizes = {"snp_ids": 80, "Region": 10, "CHR": 5,"Ref_allele" : 70, "Alt_allele":70}
     #['Region', "MiddlePosition", "snp_ids","CHR", "position", "Ref_allele", "Alt_allele", "JASS_PVAL", "UNIVARIATE_MIN_PVAL", "signif_status"]
-    region_sub_table_min_itemsizes = {"Region": 10, "index": 10, "CHR": 5, "snp_ids": 50, "signif_status":20,"Ref_allele" : 50, "Alt_allele":50}
+    region_sub_table_min_itemsizes = {"Region": 10, "index": 10, "CHR": 5, "snp_ids": 80, "signif_status":20,"Ref_allele" : 70, "Alt_allele":70}
 
     smart_na_computation = not (remove_nan)
     module_name, function_name = stat.split(":")