diff --git a/web3.js/module.flow.js b/web3.js/module.flow.js
index 03c41b0fe4..57f91cc57a 100644
--- a/web3.js/module.flow.js
+++ b/web3.js/module.flow.js
@@ -214,13 +214,13 @@ declare module '@solana/web3.js' {
   declare export type TransactionSignature = string;
 
   declare type TransactionInstructionCtorFields = {|
-    keys: ?Array<{pubkey: PublicKey, isSigner: boolean, isDebitable: boolean}>,
+    keys: ?Array<{pubkey: PublicKey, isSigner: boolean, isWritable: boolean}>,
     programId?: PublicKey,
     data?: Buffer,
   |};
 
   declare export class TransactionInstruction {
-    keys: Array<{pubkey: PublicKey, isSigner: boolean, isDebitable: boolean}>;
+    keys: Array<{pubkey: PublicKey, isSigner: boolean, isWritable: boolean}>;
     programId: PublicKey;
     data: Buffer;
 
diff --git a/web3.js/src/budget-program.js b/web3.js/src/budget-program.js
index a75aadcf28..a56661c12a 100644
--- a/web3.js/src/budget-program.js
+++ b/web3.js/src/budget-program.js
@@ -201,8 +201,8 @@ export class BudgetProgram {
 
         return transaction.add({
           keys: [
-            {pubkey: to, isSigner: false, isDebitable: false},
-            {pubkey: program, isSigner: false, isDebitable: true},
+            {pubkey: to, isSigner: false, isWritable: true},
+            {pubkey: program, isSigner: false, isWritable: true},
           ],
           programId: this.programId,
           data: trimmedData,
@@ -236,7 +236,7 @@ export class BudgetProgram {
         );
 
         return transaction.add({
-          keys: [{pubkey: program, isSigner: false, isDebitable: true}],
+          keys: [{pubkey: program, isSigner: false, isWritable: true}],
           programId: this.programId,
           data: trimmedData,
         });
@@ -269,7 +269,7 @@ export class BudgetProgram {
         );
 
         return transaction.add({
-          keys: [{pubkey: program, isSigner: false, isDebitable: true}],
+          keys: [{pubkey: program, isSigner: false, isWritable: true}],
           programId: this.programId,
           data: trimmedData,
         });
@@ -325,7 +325,7 @@ export class BudgetProgram {
     );
 
     return transaction.add({
-      keys: [{pubkey: program, isSigner: false, isDebitable: true}],
+      keys: [{pubkey: program, isSigner: false, isWritable: true}],
       programId: this.programId,
       data: trimmedData,
     });
@@ -349,9 +349,9 @@ export class BudgetProgram {
 
     return new Transaction().add({
       keys: [
-        {pubkey: from, isSigner: true, isDebitable: true},
-        {pubkey: program, isSigner: false, isDebitable: true},
-        {pubkey: to, isSigner: false, isDebitable: false},
+        {pubkey: from, isSigner: true, isWritable: true},
+        {pubkey: program, isSigner: false, isWritable: true},
+        {pubkey: to, isSigner: false, isWritable: false},
       ],
       programId: this.programId,
       data,
@@ -379,9 +379,9 @@ export class BudgetProgram {
 
     return new Transaction().add({
       keys: [
-        {pubkey: from, isSigner: true, isDebitable: true},
-        {pubkey: program, isSigner: false, isDebitable: true},
-        {pubkey: to, isSigner: false, isDebitable: false},
+        {pubkey: from, isSigner: true, isWritable: true},
+        {pubkey: program, isSigner: false, isWritable: true},
+        {pubkey: to, isSigner: false, isWritable: true},
       ],
       programId: this.programId,
       data,
diff --git a/web3.js/src/loader.js b/web3.js/src/loader.js
index 5407feca10..c840a99678 100644
--- a/web3.js/src/loader.js
+++ b/web3.js/src/loader.js
@@ -97,7 +97,7 @@ export class Loader {
       );
 
       const transaction = new Transaction().add({
-        keys: [{pubkey: program.publicKey, isSigner: true, isDebitable: true}],
+        keys: [{pubkey: program.publicKey, isSigner: true, isWritable: true}],
         programId,
         data,
       });
@@ -137,8 +137,8 @@ export class Loader {
 
       const transaction = new Transaction().add({
         keys: [
-          {pubkey: program.publicKey, isSigner: true, isDebitable: true},
-          {pubkey: SYSVAR_RENT_PUBKEY, isSigner: false, isDebitable: false},
+          {pubkey: program.publicKey, isSigner: true, isWritable: true},
+          {pubkey: SYSVAR_RENT_PUBKEY, isSigner: false, isWritable: false},
         ],
         programId,
         data,
diff --git a/web3.js/src/system-program.js b/web3.js/src/system-program.js
index 63e9f341bf..1d843e2bdb 100644
--- a/web3.js/src/system-program.js
+++ b/web3.js/src/system-program.js
@@ -183,8 +183,8 @@ export class SystemProgram {
 
     return new Transaction().add({
       keys: [
-        {pubkey: from, isSigner: true, isDebitable: true},
-        {pubkey: newAccount, isSigner: false, isDebitable: true},
+        {pubkey: from, isSigner: true, isWritable: true},
+        {pubkey: newAccount, isSigner: false, isWritable: true},
       ],
       programId: SystemProgram.programId,
       data,
@@ -200,10 +200,8 @@ export class SystemProgram {
 
     return new Transaction().add({
       keys: [
-        {pubkey: from, isSigner: true, isDebitable: true},
-        // TEMP FIX: a better proposed solution is here:
-        // https://github.com/solana-labs/solana-web3.js/issues/542
-        {pubkey: to, isSigner: false, isDebitable: true},
+        {pubkey: from, isSigner: true, isWritable: true},
+        {pubkey: to, isSigner: false, isWritable: true},
       ],
       programId: SystemProgram.programId,
       data,
@@ -218,7 +216,7 @@ export class SystemProgram {
     const data = encodeData(type, {programId: programId.toBuffer()});
 
     return new Transaction().add({
-      keys: [{pubkey: from, isSigner: true, isDebitable: true}],
+      keys: [{pubkey: from, isSigner: true, isWritable: true}],
       programId: SystemProgram.programId,
       data,
     });
diff --git a/web3.js/src/transaction.js b/web3.js/src/transaction.js
index 738c652cc2..7257fceade 100644
--- a/web3.js/src/transaction.js
+++ b/web3.js/src/transaction.js
@@ -41,7 +41,7 @@ export const PACKET_DATA_SIZE = 1280 - 40 - 8;
  * @property {?Buffer} data
  */
 export type TransactionInstructionCtorFields = {|
-  keys?: Array<{pubkey: PublicKey, isSigner: boolean, isDebitable: boolean}>,
+  keys?: Array<{pubkey: PublicKey, isSigner: boolean, isWritable: boolean}>,
   programId?: PublicKey,
   data?: Buffer,
 |};
@@ -57,7 +57,7 @@ export class TransactionInstruction {
   keys: Array<{
     pubkey: PublicKey,
     isSigner: boolean,
-    isDebitable: boolean,
+    isWritable: boolean,
   }> = [];
 
   /**
@@ -171,8 +171,8 @@ export class Transaction {
     }
 
     const keys = this.signatures.map(({publicKey}) => publicKey.toString());
-    let numCreditOnlySignedAccounts = 0;
-    let numCreditOnlyUnsignedAccounts = 0;
+    let numReadonlySignedAccounts = 0;
+    let numReadonlyUnsignedAccounts = 0;
 
     const programIds = [];
 
@@ -185,12 +185,12 @@ export class Transaction {
               signature: null,
               publicKey: keySignerPair.pubkey,
             });
-            if (!keySignerPair.isDebitable) {
-              numCreditOnlySignedAccounts += 1;
+            if (!keySignerPair.isWritable) {
+              numReadonlySignedAccounts += 1;
             }
           } else {
-            if (!keySignerPair.isDebitable) {
-              numCreditOnlyUnsignedAccounts += 1;
+            if (!keySignerPair.isWritable) {
+              numReadonlyUnsignedAccounts += 1;
             }
           }
           keys.push(keyStr);
@@ -206,7 +206,7 @@ export class Transaction {
     programIds.forEach(programId => {
       if (!keys.includes(programId)) {
         keys.push(programId);
-        numCreditOnlyUnsignedAccounts += 1;
+        numReadonlyUnsignedAccounts += 1;
       }
     });
 
@@ -274,8 +274,8 @@ export class Transaction {
 
     const signDataLayout = BufferLayout.struct([
       BufferLayout.blob(1, 'numRequiredSignatures'),
-      BufferLayout.blob(1, 'numCreditOnlySignedAccounts'),
-      BufferLayout.blob(1, 'numCreditOnlyUnsignedAccounts'),
+      BufferLayout.blob(1, 'numReadonlySignedAccounts'),
+      BufferLayout.blob(1, 'numReadonlyUnsignedAccounts'),
       BufferLayout.blob(keyCount.length, 'keyCount'),
       BufferLayout.seq(Layout.publicKey('key'), keys.length, 'keys'),
       Layout.publicKey('recentBlockhash'),
@@ -283,10 +283,8 @@ export class Transaction {
 
     const transaction = {
       numRequiredSignatures: Buffer.from([this.signatures.length]),
-      numCreditOnlySignedAccounts: Buffer.from([numCreditOnlySignedAccounts]),
-      numCreditOnlyUnsignedAccounts: Buffer.from([
-        numCreditOnlyUnsignedAccounts,
-      ]),
+      numReadonlySignedAccounts: Buffer.from([numReadonlySignedAccounts]),
+      numReadonlyUnsignedAccounts: Buffer.from([numReadonlyUnsignedAccounts]),
       keyCount: Buffer.from(keyCount),
       keys: keys.map(key => new PublicKey(key).toBuffer()),
       recentBlockhash: Buffer.from(bs58.decode(recentBlockhash)),
@@ -450,14 +448,14 @@ export class Transaction {
     function isCreditDebit(
       i: number,
       numRequiredSignatures: number,
-      numCreditOnlySignedAccounts: number,
-      numCreditOnlyUnsignedAccounts: number,
+      numReadonlySignedAccounts: number,
+      numReadonlyUnsignedAccounts: number,
       numKeys: number,
     ): boolean {
       return (
-        i < numRequiredSignatures - numCreditOnlySignedAccounts ||
+        i < numRequiredSignatures - numReadonlySignedAccounts ||
         (i >= numRequiredSignatures &&
-          i < numKeys - numCreditOnlyUnsignedAccounts)
+          i < numKeys - numReadonlyUnsignedAccounts)
       );
     }
 
@@ -476,10 +474,10 @@ export class Transaction {
 
     const numRequiredSignatures = byteArray.shift();
     // byteArray = byteArray.slice(1); // Skip numRequiredSignatures byte
-    const numCreditOnlySignedAccounts = byteArray.shift();
-    // byteArray = byteArray.slice(1); // Skip numCreditOnlySignedAccounts byte
-    const numCreditOnlyUnsignedAccounts = byteArray.shift();
-    // byteArray = byteArray.slice(1); // Skip numCreditOnlyUnsignedAccounts byte
+    const numReadonlySignedAccounts = byteArray.shift();
+    // byteArray = byteArray.slice(1); // Skip numReadonlySignedAccounts byte
+    const numReadonlyUnsignedAccounts = byteArray.shift();
+    // byteArray = byteArray.slice(1); // Skip numReadonlyUnsignedAccounts byte
 
     const accountCount = shortvec.decodeLength(byteArray);
     let accounts = [];
@@ -532,11 +530,11 @@ export class Transaction {
           isSigner: transaction.signatures.some(
             keyObj => keyObj.publicKey.toString() === pubkey.toString(),
           ),
-          isDebitable: isCreditDebit(
+          isWritable: isCreditDebit(
             j,
             numRequiredSignatures,
-            numCreditOnlySignedAccounts,
-            numCreditOnlyUnsignedAccounts,
+            numReadonlySignedAccounts,
+            numReadonlyUnsignedAccounts,
             accounts.length,
           ),
         });
diff --git a/web3.js/test/bpf-loader.test.js b/web3.js/test/bpf-loader.test.js
index 4a63e755b3..b69c5bd0dc 100644
--- a/web3.js/test/bpf-loader.test.js
+++ b/web3.js/test/bpf-loader.test.js
@@ -36,7 +36,7 @@ test('load BPF C program', async () => {
 
   const programId = await BpfLoader.load(connection, from, data);
   const transaction = new Transaction().add({
-    keys: [{pubkey: from.publicKey, isSigner: true, isDebitable: true}],
+    keys: [{pubkey: from.publicKey, isSigner: true, isWritable: true}],
     programId,
   });
   await sendAndConfirmTransaction(connection, transaction, from);
@@ -61,7 +61,7 @@ test('load BPF Rust program', async () => {
 
   const programId = await BpfLoader.load(connection, from, data);
   const transaction = new Transaction().add({
-    keys: [{pubkey: from.publicKey, isSigner: true, isDebitable: true}],
+    keys: [{pubkey: from.publicKey, isSigner: true, isWritable: true}],
     programId,
   });
   await sendAndConfirmTransaction(connection, transaction, from);
diff --git a/web3.js/test/connection.test.js b/web3.js/test/connection.test.js
index 47e4630321..95863cfd6c 100644
--- a/web3.js/test/connection.test.js
+++ b/web3.js/test/connection.test.js
@@ -681,11 +681,6 @@ test('transaction', async () => {
       result: 31,
     },
   ]);
-  if (!mockRpcEnabled) {
-    // Credit-only account credits are committed at the end of every slot;
-    // this sleep is to ensure a full slot has elapsed
-    await sleep((1000 * DEFAULT_TICKS_PER_SLOT) / NUM_TICKS_PER_SECOND);
-  }
   expect(await connection.getBalance(accountTo.publicKey)).toBe(31);
 });
 
diff --git a/web3.js/test/system-program.test.js b/web3.js/test/system-program.test.js
index 869996eb98..8965628dd3 100644
--- a/web3.js/test/system-program.test.js
+++ b/web3.js/test/system-program.test.js
@@ -111,8 +111,8 @@ test('non-SystemInstruction error', () => {
 
   const badProgramId = {
     keys: [
-      {pubkey: from.publicKey, isSigner: true, isDebitable: true},
-      {pubkey: to.publicKey, isSigner: false, isDebitable: false},
+      {pubkey: from.publicKey, isSigner: true, isWritable: true},
+      {pubkey: to.publicKey, isSigner: false, isWritable: true},
     ],
     programId: BudgetProgram.programId,
     data: Buffer.from([2, 0, 0, 0]),