diff --git a/.github/workflows/soroban-rpc.yml b/.github/workflows/soroban-rpc.yml
index af1734961..b1eb29546 100644
--- a/.github/workflows/soroban-rpc.yml
+++ b/.github/workflows/soroban-rpc.yml
@@ -90,7 +90,7 @@ jobs:
     env:
       SOROBAN_RPC_INTEGRATION_TESTS_ENABLED: true
       SOROBAN_RPC_INTEGRATION_TESTS_CAPTIVE_CORE_BIN: /usr/bin/stellar-core
-      PROTOCOL_20_CORE_DEBIAN_PKG_VERSION: 19.7.1-1204.871accefc.focal~soroban
+      PROTOCOL_20_CORE_DEBIAN_PKG_VERSION: 19.8.1-1238.903afe5e1.focal~soroban
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
diff --git a/cmd/soroban-rpc/internal/methods/get_events_test.go b/cmd/soroban-rpc/internal/methods/get_events_test.go
index 21bac97f9..00898c5ba 100644
--- a/cmd/soroban-rpc/internal/methods/get_events_test.go
+++ b/cmd/soroban-rpc/internal/methods/get_events_test.go
@@ -22,10 +22,10 @@ func TestTopicFilterMatches(t *testing.T) {
 		Type: xdr.ScValTypeScvSymbol,
 		Sym:  &transferSym,
 	}
-	sixtyfour := xdr.Int64(64)
+	sixtyfour := xdr.Uint64(64)
 	number := xdr.ScVal{
-		Type: xdr.ScValTypeScvU63,
-		U63:  &sixtyfour,
+		Type: xdr.ScValTypeScvU64,
+		U64:  &sixtyfour,
 	}
 	star := "*"
 	for _, tc := range []struct {
@@ -191,8 +191,8 @@ func TestTopicFilterJSON(t *testing.T) {
 	assert.NoError(t, json.Unmarshal([]byte("[\"*\"]"), &got))
 	assert.Equal(t, TopicFilter{{wildcard: &star}}, got)
 
-	sixtyfour := xdr.Int64(64)
-	scval := xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &sixtyfour}
+	sixtyfour := xdr.Uint64(64)
+	scval := xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &sixtyfour}
 	scvalstr, err := xdr.MarshalBase64(scval)
 	assert.NoError(t, err)
 	assert.NoError(t, json.Unmarshal([]byte(fmt.Sprintf("[%q]", scvalstr)), &got))
@@ -514,7 +514,7 @@ func TestGetEvents(t *testing.T) {
 		var txMeta []xdr.TransactionMeta
 		contractID := xdr.Hash([32]byte{})
 		for i := 0; i < 10; i++ {
-			number := xdr.Int64(i)
+			number := xdr.Uint64(i)
 			txMeta = append(txMeta, transactionMetaWithEvents(
 				[]xdr.ContractEvent{
 					// Generate a unique topic like /counter/4 for each event so we can check
@@ -522,16 +522,16 @@ func TestGetEvents(t *testing.T) {
 						contractID,
 						xdr.ScVec{
 							xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter},
-							xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+							xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 						},
-						xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+						xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 					),
 				},
 			))
 		}
 		assert.NoError(t, store.IngestEvents(ledgerCloseMetaWithEvents(1, now.Unix(), txMeta...)))
 
-		number := xdr.Int64(4)
+		number := xdr.Uint64(4)
 		handler := eventsRPCHandler{
 			scanner:      store,
 			maxLimit:     10000,
@@ -543,7 +543,7 @@ func TestGetEvents(t *testing.T) {
 				{Topics: []TopicFilter{
 					[]SegmentFilter{
 						{scval: &xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter}},
-						{scval: &xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number}},
+						{scval: &xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number}},
 					},
 				}},
 			},
@@ -553,8 +553,8 @@ func TestGetEvents(t *testing.T) {
 		id := events.Cursor{Ledger: 1, Tx: 5, Op: 0, Event: 0}.String()
 		assert.NoError(t, err)
 		value, err := xdr.MarshalBase64(xdr.ScVal{
-			Type: xdr.ScValTypeScvU63,
-			U63:  &number,
+			Type: xdr.ScValTypeScvU64,
+			U64:  &number,
 		})
 		assert.NoError(t, err)
 		expected := []EventInfo{
@@ -576,7 +576,7 @@ func TestGetEvents(t *testing.T) {
 		store := events.NewMemoryStore("unit-tests", 100)
 		contractID := xdr.Hash([32]byte{})
 		otherContractID := xdr.Hash([32]byte{1})
-		number := xdr.Int64(1)
+		number := xdr.Uint64(1)
 		txMeta := []xdr.TransactionMeta{
 			// This matches neither the contract id nor the topic
 			transactionMetaWithEvents([]xdr.ContractEvent{
@@ -585,7 +585,7 @@ func TestGetEvents(t *testing.T) {
 					xdr.ScVec{
 						xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter},
 					},
-					xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+					xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 				),
 			}),
 			// This matches the contract id but not the topic
@@ -595,7 +595,7 @@ func TestGetEvents(t *testing.T) {
 					xdr.ScVec{
 						xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter},
 					},
-					xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+					xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 				),
 			}),
 			// This matches the topic but not the contract id
@@ -604,9 +604,9 @@ func TestGetEvents(t *testing.T) {
 					otherContractID,
 					xdr.ScVec{
 						xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter},
-						xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+						xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 					},
-					xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+					xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 				),
 			}),
 			// This matches both the contract id and the topic
@@ -615,9 +615,9 @@ func TestGetEvents(t *testing.T) {
 					contractID,
 					xdr.ScVec{
 						xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter},
-						xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+						xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 					},
-					xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+					xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 				),
 			}),
 		}
@@ -636,7 +636,7 @@ func TestGetEvents(t *testing.T) {
 					Topics: []TopicFilter{
 						[]SegmentFilter{
 							{scval: &xdr.ScVal{Type: xdr.ScValTypeScvSymbol, Sym: &counter}},
-							{scval: &xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number}},
+							{scval: &xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number}},
 						},
 					},
 				},
@@ -646,8 +646,8 @@ func TestGetEvents(t *testing.T) {
 
 		id := events.Cursor{Ledger: 1, Tx: 4, Op: 0, Event: 0}.String()
 		value, err := xdr.MarshalBase64(xdr.ScVal{
-			Type: xdr.ScValTypeScvU63,
-			U63:  &number,
+			Type: xdr.ScValTypeScvU64,
+			U64:  &number,
 		})
 		assert.NoError(t, err)
 		expected := []EventInfo{
@@ -722,15 +722,15 @@ func TestGetEvents(t *testing.T) {
 		contractID := xdr.Hash([32]byte{})
 		var txMeta []xdr.TransactionMeta
 		for i := 0; i < 180; i++ {
-			number := xdr.Int64(i)
+			number := xdr.Uint64(i)
 			txMeta = append(txMeta, transactionMetaWithEvents(
 				[]xdr.ContractEvent{
 					contractEvent(
 						contractID,
 						xdr.ScVec{
-							xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+							xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 						},
-						xdr.ScVal{Type: xdr.ScValTypeScvU63, U63: &number},
+						xdr.ScVal{Type: xdr.ScValTypeScvU64, U64: &number},
 					),
 				},
 			))
diff --git a/cmd/soroban-rpc/internal/test/docker-compose.yml b/cmd/soroban-rpc/internal/test/docker-compose.yml
index f6a9a9622..3bc8171fa 100644
--- a/cmd/soroban-rpc/internal/test/docker-compose.yml
+++ b/cmd/soroban-rpc/internal/test/docker-compose.yml
@@ -15,7 +15,7 @@ services:
     # Note: Please keep the image pinned to an immutable tag matching the Captive Core version.
     #       This avoid implicit updates which break compatibility between
     #       the Core container and captive core.
-    image: ${CORE_IMAGE:-2opremio/stellar-core:19.7.1-1178.e352f0012.focal-soroban}
+    image: ${CORE_IMAGE:-2opremio/stellar-core:19.8.1-1238.903afe5e1.focal-soroban}
     depends_on:
       - core-postgres
     restart: on-failure
diff --git a/cmd/soroban-rpc/internal/test/get_ledger_entry_test.go b/cmd/soroban-rpc/internal/test/get_ledger_entry_test.go
index 606a1b54e..40e0a07a0 100644
--- a/cmd/soroban-rpc/internal/test/get_ledger_entry_test.go
+++ b/cmd/soroban-rpc/internal/test/get_ledger_entry_test.go
@@ -31,7 +31,9 @@ func TestGetLedgerEntryNotFound(t *testing.T) {
 		Type: xdr.LedgerEntryTypeContractData,
 		ContractData: &xdr.LedgerKeyContractData{
 			ContractId: contractID,
-			Key:        getContractCodeLedgerKey(),
+			Key: xdr.ScVal{
+				Type: xdr.ScValTypeScvLedgerKeyContractExecutable,
+			},
 		},
 	})
 	require.NoError(t, err)
diff --git a/cmd/soroban-rpc/internal/test/simulate_transaction_test.go b/cmd/soroban-rpc/internal/test/simulate_transaction_test.go
index 5943e13fd..30c6a0030 100644
--- a/cmd/soroban-rpc/internal/test/simulate_transaction_test.go
+++ b/cmd/soroban-rpc/internal/test/simulate_transaction_test.go
@@ -37,16 +37,12 @@ func getHelloWorldContract(t *testing.T) []byte {
 }
 
 func createInvokeHostOperation(sourceAccount string, footprint xdr.LedgerFootprint, contractID xdr.Hash, method string, args ...xdr.ScVal) *txnbuild.InvokeHostFunction {
-	var contractIDBytes []byte = contractID[:]
-	contractIDObj := &xdr.ScObject{
-		Type: xdr.ScObjectTypeScoBytes,
-		Bin:  &contractIDBytes,
-	}
+	var contractIDBytes = xdr.ScBytes(contractID[:])
 	methodSymbol := xdr.ScSymbol(method)
 	parameters := xdr.ScVec{
 		xdr.ScVal{
-			Type: xdr.ScValTypeScvObject,
-			Obj:  &contractIDObj,
+			Type:  xdr.ScValTypeScvBytes,
+			Bytes: &contractIDBytes,
 		},
 		xdr.ScVal{
 			Type: xdr.ScValTypeScvSymbol,
@@ -108,7 +104,9 @@ func createCreateContractOperation(t *testing.T, sourceAccount string, contractC
 					Type: xdr.LedgerEntryTypeContractData,
 					ContractData: &xdr.LedgerKeyContractData{
 						ContractId: xdr.Hash(getContractID(t, sourceAccount, testSalt, networkPassphrase)),
-						Key:        getContractCodeLedgerKey(),
+						Key: xdr.ScVal{
+							Type: xdr.ScValTypeScvLedgerKeyContractExecutable,
+						},
 					},
 				},
 			},
@@ -136,8 +134,8 @@ func createCreateContractOperation(t *testing.T, sourceAccount string, contractC
 					Type: xdr.ContractIdTypeContractIdFromSourceAccount,
 					Salt: &saltParam,
 				},
-				Source: xdr.ScContractCode{
-					Type:   xdr.ScContractCodeTypeSccontractCodeWasmRef,
+				Source: xdr.ScContractExecutable{
+					Type:   xdr.ScContractExecutableTypeSccontractExecutableWasmRef,
 					WasmId: &contractHash,
 				},
 			},
@@ -146,15 +144,6 @@ func createCreateContractOperation(t *testing.T, sourceAccount string, contractC
 	}
 }
 
-func getContractCodeLedgerKey() xdr.ScVal {
-	ledgerKeyContractCodeAddr := xdr.ScStaticScsLedgerKeyContractCode
-	contractCodeLedgerKey := xdr.ScVal{
-		Type: xdr.ScValTypeScvStatic,
-		Ic:   &ledgerKeyContractCodeAddr,
-	}
-	return contractCodeLedgerKey
-}
-
 func getContractID(t *testing.T, sourceAccount string, salt [32]byte, networkPassphrase string) [32]byte {
 	networkID := xdr.Hash(sha256.Sum256([]byte(networkPassphrase)))
 	preImage := xdr.HashIdPreimage{
@@ -341,13 +330,6 @@ func TestSimulateInvokeContractTransactionSucceeds(t *testing.T) {
 	})
 	assert.NoError(t, err)
 	sendSuccessfulTransaction(t, client, sourceAccount, tx)
-	addressObject := &xdr.ScObject{
-		Type: xdr.ScObjectTypeScoAddress,
-		Address: &xdr.ScAddress{
-			Type:      xdr.ScAddressTypeScAddressTypeAccount,
-			AccountId: &authAccountIDArg,
-		},
-	}
 	tx, err = txnbuild.NewTransaction(txnbuild.TransactionParams{
 		SourceAccount:        &account,
 		IncrementSequenceNum: true,
@@ -358,8 +340,11 @@ func TestSimulateInvokeContractTransactionSucceeds(t *testing.T) {
 				contractID,
 				"auth",
 				xdr.ScVal{
-					Type: xdr.ScValTypeScvObject,
-					Obj:  &addressObject,
+					Type: xdr.ScValTypeScvAddress,
+					Address: &xdr.ScAddress{
+						Type:      xdr.ScAddressTypeScAddressTypeAccount,
+						AccountId: &authAccountIDArg,
+					},
 				},
 				xdr.ScVal{
 					Type: xdr.ScValTypeScvSymbol,
@@ -387,11 +372,10 @@ func TestSimulateInvokeContractTransactionSucceeds(t *testing.T) {
 	var obtainedResult xdr.ScVal
 	err = xdr.SafeUnmarshalBase64(response.Results[0].XDR, &obtainedResult)
 	assert.NoError(t, err)
-	assert.Equal(t, xdr.ScValTypeScvObject, obtainedResult.Type)
-	obj := *obtainedResult.Obj
-	assert.Equal(t, xdr.ScObjectTypeScoVec, obj.Type)
-	assert.Len(t, *obj.Vec, 2)
-	world := (*obj.Vec)[1]
+	assert.Equal(t, xdr.ScValTypeScvVec, obtainedResult.Type)
+	assert.NotNil(t, *obtainedResult.Vec)
+	assert.Len(t, **obtainedResult.Vec, 2)
+	world := (**obtainedResult.Vec)[1]
 	assert.Equal(t, xdr.ScValTypeScvSymbol, world.Type)
 	assert.Equal(t, xdr.ScSymbol("world"), *world.Sym)
 
@@ -407,8 +391,7 @@ func TestSimulateInvokeContractTransactionSucceeds(t *testing.T) {
 	ro1 := obtainedFootprint.ReadOnly[1]
 	assert.Equal(t, xdr.LedgerEntryTypeContractData, ro1.Type)
 	assert.Equal(t, xdr.Hash(contractID), ro1.ContractData.ContractId)
-	assert.Equal(t, xdr.ScValTypeScvStatic, ro1.ContractData.Key.Type)
-	assert.Equal(t, xdr.ScStaticScsLedgerKeyContractCode, *ro1.ContractData.Key.Ic)
+	assert.Equal(t, xdr.ScValTypeScvLedgerKeyContractExecutable, ro1.ContractData.Key.Type)
 	ro2 := obtainedFootprint.ReadOnly[2]
 	assert.Equal(t, xdr.LedgerEntryTypeContractCode, ro2.Type)
 	installContractCodeArgs, err := xdr.InstallContractCodeArgs{Code: helloWorldContract}.MarshalBinary()
diff --git a/cmd/soroban-rpc/internal/test/transaction_test.go b/cmd/soroban-rpc/internal/test/transaction_test.go
index 44f8f2119..467677f96 100644
--- a/cmd/soroban-rpc/internal/test/transaction_test.go
+++ b/cmd/soroban-rpc/internal/test/transaction_test.go
@@ -80,8 +80,8 @@ func TestSendTransactionSucceedsWithResults(t *testing.T) {
 	resultVal := *invokeHostFunctionResult.Success
 	expectedContractID, err := hex.DecodeString("ea9fcb81ae54a29f6b3bf293847d3fd7e9a369fd1c80acafec6abd571317e0c2")
 	assert.NoError(t, err)
-	expectedObj := &xdr.ScObject{Type: xdr.ScObjectTypeScoBytes, Bin: &expectedContractID}
-	expectedScVal := xdr.ScVal{Type: xdr.ScValTypeScvObject, Obj: &expectedObj}
+	contractIDBytes := xdr.ScBytes(expectedContractID)
+	expectedScVal := xdr.ScVal{Type: xdr.ScValTypeScvBytes, Bytes: &contractIDBytes}
 	assert.True(t, expectedScVal.Equals(resultVal))
 
 	expectedResult := xdr.TransactionResult{
diff --git a/go.mod b/go.mod
index 93ea4e91f..ba435e2ca 100644
--- a/go.mod
+++ b/go.mod
@@ -14,7 +14,7 @@ require (
 	github.com/sirupsen/logrus v1.4.1
 	github.com/spf13/cobra v0.0.0-20160830174925-9c28e4bbd74e
 	github.com/spf13/viper v0.0.0-20150621231900-db7ff930a189
-	github.com/stellar/go v0.0.0-20230307175517-b2d1e113c534
+	github.com/stellar/go v0.0.0-20230320165241-a5f3278b8282
 	github.com/stretchr/testify v1.8.0
 	golang.org/x/mod v0.6.0
 )
diff --git a/go.sum b/go.sum
index afaf98c79..da919561c 100644
--- a/go.sum
+++ b/go.sum
@@ -167,8 +167,8 @@ github.com/spf13/pflag v0.0.0-20161005214240-4bd69631f475 h1:RtZIgreTwcayPTOw7G5
 github.com/spf13/pflag v0.0.0-20161005214240-4bd69631f475/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/viper v0.0.0-20150621231900-db7ff930a189 h1:fvB1AFbBd6SfI9Rd0ooAJp8uLkZDbZaLFHi7ZnNP6uI=
 github.com/spf13/viper v0.0.0-20150621231900-db7ff930a189/go.mod h1:A8kyI5cUJhb8N+3pkfONlcEcZbueH6nhAm0Fq7SrnBM=
-github.com/stellar/go v0.0.0-20230307175517-b2d1e113c534 h1:ecxXXWGTHRY765WueJi8QCN21Ckxb0XNIRDbNbZ5TG4=
-github.com/stellar/go v0.0.0-20230307175517-b2d1e113c534/go.mod h1:QXwuKmYVvqQZlByv0EeNb0Rgog9AP+eMmARcdt3h2rI=
+github.com/stellar/go v0.0.0-20230320165241-a5f3278b8282 h1:Lijy4+s8ZwC6omEHHI4zThxxqKkQ0q1JyUn0WLfKFgI=
+github.com/stellar/go v0.0.0-20230320165241-a5f3278b8282/go.mod h1:QXwuKmYVvqQZlByv0EeNb0Rgog9AP+eMmARcdt3h2rI=
 github.com/stellar/go-xdr v0.0.0-20211103144802-8017fc4bdfee h1:fbVs0xmXpBvVS4GBeiRmAE3Le70ofAqFMch1GTiq/e8=
 github.com/stellar/go-xdr v0.0.0-20211103144802-8017fc4bdfee/go.mod h1:yoxyU/M8nl9LKeWIoBrbDPQ7Cy+4jxRcWcOayZ4BMps=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=