diff --git a/src/bin_client/test/test_contracts.sh b/src/bin_client/test/test_contracts.sh
index 52dadcd72..3ece51686 100755
--- a/src/bin_client/test/test_contracts.sh
+++ b/src/bin_client/test/test_contracts.sh
@@ -401,7 +401,7 @@ init_with_transfer $contract_dir/create_contract.tz $key2 Unit 1,000 bootstrap1
 created_contract=\
 `$client transfer 0 from bootstrap1 to create_contract -arg '(Left "tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx")' \
 | grep 'New contract' \
-| sed -E 's/.*(TZ1[a-zA-Z0-9]+).*/\1/' \
+| sed -E 's/.*(KT1[a-zA-Z0-9]+).*/\1/' \
 | head -1`
 bake
 assert_storage_contains $created_contract '"abcdefg"'
diff --git a/src/proto_alpha/lib_protocol/src/contract_hash.ml b/src/proto_alpha/lib_protocol/src/contract_hash.ml
index 689fee038..77915f843 100644
--- a/src/proto_alpha/lib_protocol/src/contract_hash.ml
+++ b/src/proto_alpha/lib_protocol/src/contract_hash.ml
@@ -8,7 +8,7 @@
 (**************************************************************************)
 
 (* 20 *)
-let contract_hash = "\003\099\029" (* TZ(36) *)
+let contract_hash = "\002\090\121" (* KT1(36) *)
 
 include Blake2B.Make(Base58)(struct
     let name = "Contract_hash"
@@ -18,4 +18,4 @@ include Blake2B.Make(Base58)(struct
   end)
 
 let () =
-  Base58.check_encoded_prefix b58check_encoding "TZ1" 36
+  Base58.check_encoded_prefix b58check_encoding "KT1" 36