diff --git a/src/proto_alpha/lib_protocol/src/constants_repr.ml b/src/proto_alpha/lib_protocol/src/constants_repr.ml
index 8ccaaee8..b88c1ae7 100644
--- a/src/proto_alpha/lib_protocol/src/constants_repr.ml
+++ b/src/proto_alpha/lib_protocol/src/constants_repr.ml
@@ -68,12 +68,12 @@ let read_public_key s = Ed25519.Public_key.of_hex_exn (`Hex s)
 
 let default = {
   preserved_cycles = 5 ;
-  blocks_per_cycle = 4096l ;
-  blocks_per_commitment = 32l ;
-  blocks_per_roll_snapshot = 256l ;
-  blocks_per_voting_period = 32768l ;
+  blocks_per_cycle = 128l ;
+  blocks_per_commitment = 8l ;
+  blocks_per_roll_snapshot = 32l ;
+  blocks_per_voting_period = 1024l ;
   time_between_blocks =
-    List.map Period_repr.of_seconds_exn [ 60L ] ;
+    List.map Period_repr.of_seconds_exn [ 60L ; 30L ; 20L ; 10L ] ;
   first_free_baking_slot = 16 ;
   endorsers_per_block = 32 ;
   max_gas = 40_000 ;