diff --git a/src/lib_shell/state.ml b/src/lib_shell/state.ml
index 7740042bb..7f3b9d696 100644
--- a/src/lib_shell/state.ml
+++ b/src/lib_shell/state.ml
@@ -1287,8 +1287,8 @@ let read
 
 let init
     ?patch_context
-    ?(store_mapsize=4_096_000_000_000L)
-    ?(context_mapsize=40_960_000_000L)
+    ?(store_mapsize=40_960_000_000L)
+    ?(context_mapsize=409_600_000_000L)
     ~store_root
     ~context_root
     genesis =
diff --git a/vendors/irmin-lmdb/irmin_lmdb.ml b/vendors/irmin-lmdb/irmin_lmdb.ml
index 9bf0f1452..276e29f9f 100644
--- a/vendors/irmin-lmdb/irmin_lmdb.ml
+++ b/vendors/irmin-lmdb/irmin_lmdb.ml
@@ -104,7 +104,7 @@ module Conf = struct
 
   let root = Irmin.Private.Conf.root
   let mapsize =
-    Irmin.Private.Conf.key "mapsize" int64_converter 40_960_000_000L
+    Irmin.Private.Conf.key "mapsize" int64_converter 409_600_000_000L
   let readonly = 
     Irmin.Private.Conf.key "readonly" bool_converter false