diff --git a/Cargo.lock b/Cargo.lock
index 2da712d30..6bec0bc38 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1102,8 +1102,8 @@ checksum = "a507befe795404456341dfab10cef66ead4c041f62b8b11bbb92bffe5d0953e0"
 
 [[package]]
 name = "soroban-env-common"
-version = "0.0.17"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=66a3c504387da5bb5bb0b1cc4b0beb22c74fb252#66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+version = "20.0.0-rc1"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=f19ef13363a1e0cbff7b100c0599a1d63dea88a6#f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 dependencies = [
  "arbitrary",
  "crate-git-revision",
@@ -1119,8 +1119,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-guest"
-version = "0.0.17"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=66a3c504387da5bb5bb0b1cc4b0beb22c74fb252#66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+version = "20.0.0-rc1"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=f19ef13363a1e0cbff7b100c0599a1d63dea88a6#f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 dependencies = [
  "soroban-env-common",
  "static_assertions",
@@ -1128,8 +1128,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-host"
-version = "0.0.17"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=66a3c504387da5bb5bb0b1cc4b0beb22c74fb252#66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+version = "20.0.0-rc1"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=f19ef13363a1e0cbff7b100c0599a1d63dea88a6#f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 dependencies = [
  "backtrace",
  "ed25519-dalek",
@@ -1151,8 +1151,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-env-macros"
-version = "0.0.17"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=66a3c504387da5bb5bb0b1cc4b0beb22c74fb252#66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+version = "20.0.0-rc1"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=f19ef13363a1e0cbff7b100c0599a1d63dea88a6#f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 dependencies = [
  "itertools",
  "proc-macro2",
@@ -1165,7 +1165,7 @@ dependencies = [
 
 [[package]]
 name = "soroban-ledger-snapshot"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "pretty_assertions",
  "serde",
@@ -1177,8 +1177,8 @@ dependencies = [
 
 [[package]]
 name = "soroban-native-sdk-macros"
-version = "0.0.17"
-source = "git+https://github.com/stellar/rs-soroban-env?rev=66a3c504387da5bb5bb0b1cc4b0beb22c74fb252#66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+version = "20.0.0-rc1"
+source = "git+https://github.com/stellar/rs-soroban-env?rev=f19ef13363a1e0cbff7b100c0599a1d63dea88a6#f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 dependencies = [
  "itertools",
  "proc-macro2",
@@ -1188,7 +1188,7 @@ dependencies = [
 
 [[package]]
 name = "soroban-sdk"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "arbitrary",
  "bytes-lit",
@@ -1209,7 +1209,7 @@ dependencies = [
 
 [[package]]
 name = "soroban-sdk-macros"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "crate-git-revision",
  "darling",
@@ -1227,7 +1227,7 @@ dependencies = [
 
 [[package]]
 name = "soroban-spec"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "base64 0.13.1",
  "pretty_assertions",
@@ -1238,7 +1238,7 @@ dependencies = [
 
 [[package]]
 name = "soroban-spec-rust"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "pretty_assertions",
  "prettyplease",
@@ -1253,15 +1253,15 @@ dependencies = [
 
 [[package]]
 name = "soroban-token-sdk"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "soroban-wasmi"
-version = "0.30.0-soroban"
-source = "git+https://github.com/stellar/wasmi?rev=284c963ba080703061797e2a3cba0853edee0dd4#284c963ba080703061797e2a3cba0853edee0dd4"
+version = "0.31.0-soroban1"
+source = "git+https://github.com/stellar/wasmi?rev=7e63b4c9e08c4163f417d118d81f7ea34789d0be#7e63b4c9e08c4163f417d118d81f7ea34789d0be"
 dependencies = [
  "smallvec",
  "spin",
@@ -1303,8 +1303,8 @@ dependencies = [
 
 [[package]]
 name = "stellar-xdr"
-version = "0.0.17"
-source = "git+https://github.com/stellar/rs-stellar-xdr?rev=84d4d01f739b4f2c3f445f41bc7464a5621ba58c#84d4d01f739b4f2c3f445f41bc7464a5621ba58c"
+version = "20.0.0-rc1"
+source = "git+https://github.com/stellar/rs-stellar-xdr?rev=d5ce0c9e7aa83461773a6e81662067f35d39e4c1#d5ce0c9e7aa83461773a6e81662067f35d39e4c1"
 dependencies = [
  "arbitrary",
  "base64 0.13.1",
@@ -1364,119 +1364,119 @@ dependencies = [
 
 [[package]]
 name = "test_add_i128"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_add_u128"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_add_u64"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_alloc"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_auth"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_contract_data"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_empty"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_empty2"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_errors"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_events"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_fuzz"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_import_contract"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_invoke_contract"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_logging"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_multiimpl"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_udt"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
 
 [[package]]
 name = "test_workspace_contract"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
  "test_workspace_lib",
@@ -1484,7 +1484,7 @@ dependencies = [
 
 [[package]]
 name = "test_workspace_lib"
-version = "0.9.2"
+version = "20.0.0-rc1"
 dependencies = [
  "soroban-sdk",
 ]
@@ -1632,12 +1632,12 @@ checksum = "ca6ad05a4870b2bf5fe995117d3728437bd27d7cd5f06f13c17443ef369775a1"
 [[package]]
 name = "wasmi_arena"
 version = "0.4.0"
-source = "git+https://github.com/stellar/wasmi?rev=284c963ba080703061797e2a3cba0853edee0dd4#284c963ba080703061797e2a3cba0853edee0dd4"
+source = "git+https://github.com/stellar/wasmi?rev=7e63b4c9e08c4163f417d118d81f7ea34789d0be#7e63b4c9e08c4163f417d118d81f7ea34789d0be"
 
 [[package]]
 name = "wasmi_core"
-version = "0.12.0"
-source = "git+https://github.com/stellar/wasmi?rev=284c963ba080703061797e2a3cba0853edee0dd4#284c963ba080703061797e2a3cba0853edee0dd4"
+version = "0.13.0"
+source = "git+https://github.com/stellar/wasmi?rev=7e63b4c9e08c4163f417d118d81f7ea34789d0be#7e63b4c9e08c4163f417d118d81f7ea34789d0be"
 dependencies = [
  "downcast-rs",
  "libm",
diff --git a/Cargo.toml b/Cargo.toml
index 9d2988887..c50cf2e2c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,30 +29,30 @@ members = [
 ]
 
 [workspace.package]
-version = "0.9.2"
+version = "20.0.0-rc1"
 
 [workspace.dependencies]
-soroban-sdk = { version = "0.9.2", path = "soroban-sdk" }
-soroban-sdk-macros = { version = "0.9.2", path = "soroban-sdk-macros" }
-soroban-spec = { version = "0.9.2", path = "soroban-spec" }
-soroban-spec-rust = { version = "0.9.2", path = "soroban-spec-rust" }
-soroban-ledger-snapshot = { version = "0.9.2", path = "soroban-ledger-snapshot" }
-soroban-token-sdk = { version = "0.9.2", path = "soroban-token-sdk" }
+soroban-sdk = { version = "20.0.0-rc1", path = "soroban-sdk" }
+soroban-sdk-macros = { version = "20.0.0-rc1", path = "soroban-sdk-macros" }
+soroban-spec = { version = "20.0.0-rc1", path = "soroban-spec" }
+soroban-spec-rust = { version = "20.0.0-rc1", path = "soroban-spec-rust" }
+soroban-ledger-snapshot = { version = "20.0.0-rc1", path = "soroban-ledger-snapshot" }
+soroban-token-sdk = { version = "20.0.0-rc1", path = "soroban-token-sdk" }
 
 [workspace.dependencies.soroban-env-common]
-version = "0.0.17"
+version = "20.0.0-rc1"
 git = "https://github.com/stellar/rs-soroban-env"
-rev = "66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+rev = "f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 
 [workspace.dependencies.soroban-env-guest]
-version = "0.0.17"
+version = "20.0.0-rc1"
 git = "https://github.com/stellar/rs-soroban-env"
-rev = "66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+rev = "f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 
 [workspace.dependencies.soroban-env-host]
-version = "0.0.17"
+version = "20.0.0-rc1"
 git = "https://github.com/stellar/rs-soroban-env"
-rev = "66a3c504387da5bb5bb0b1cc4b0beb22c74fb252"
+rev = "f19ef13363a1e0cbff7b100c0599a1d63dea88a6"
 
 [workspace.dependencies.stellar-strkey]
 version = "0.0.7"
@@ -60,9 +60,9 @@ git = "https://github.com/stellar/rs-stellar-strkey"
 rev = "e6ba45c60c16de28c7522586b80ed0150157df73"
 
 [workspace.dependencies.stellar-xdr]
-version = "0.0.17"
+version = "20.0.0-rc1"
 git = "https://github.com/stellar/rs-stellar-xdr"
-rev = "84d4d01f739b4f2c3f445f41bc7464a5621ba58c"
+rev = "d5ce0c9e7aa83461773a6e81662067f35d39e4c1"
 default-features = false
 features = ["curr"]
 
diff --git a/soroban-sdk/src/deploy.rs b/soroban-sdk/src/deploy.rs
index 71378ccff..01401705f 100644
--- a/soroban-sdk/src/deploy.rs
+++ b/soroban-sdk/src/deploy.rs
@@ -31,7 +31,7 @@
 //! #     let env = Env::default();
 //! #     let contract_address = env.register_contract(None, Contract);
 //! #     // Install the contract code before deploying its instance.
-//! #     let mock_wasm = [0u8; 100];
+//! #     let mock_wasm = [0u8; 0];
 //! #     let wasm_hash = env.deployer().upload_contract_wasm(mock_wasm.as_slice());
 //! #     ContractClient::new(&env, &contract_address).f(&wasm_hash);
 //! # }
diff --git a/soroban-sdk/src/env.rs b/soroban-sdk/src/env.rs
index 4ed0e7cf2..2d40f6104 100644
--- a/soroban-sdk/src/env.rs
+++ b/soroban-sdk/src/env.rs
@@ -524,7 +524,7 @@ impl Env {
         };
 
         env.ledger().set(internal::LedgerInfo {
-            protocol_version: 0,
+            protocol_version: 20,
             sequence_number: 0,
             timestamp: 0,
             network_id: [0; 32],