diff --git a/packages/client/lib/client/index.spec.ts b/packages/client/lib/client/index.spec.ts
index 51dded18b1..3f0bca45e2 100644
--- a/packages/client/lib/client/index.spec.ts
+++ b/packages/client/lib/client/index.spec.ts
@@ -1,6 +1,6 @@
 import { strict as assert } from 'assert';
 import testUtils, { GLOBAL, waitTillBeenCalled } from '../test-utils';
-import RedisClient, { RedisClientType } from '.';
+import RedisClient, { ClientLegacyCommandArguments, RedisClientType } from '.';
 import { RedisClientMultiCommandType } from './multi-command';
 import { RedisCommandArguments, RedisCommandRawReply, RedisModules, RedisScripts } from '../commands';
 import { AbortError, ClientClosedError, ConnectionTimeoutError, DisconnectsClientError, SocketClosedUnexpectedlyError, WatchError } from '../errors';
@@ -170,7 +170,7 @@ describe('Client', () => {
             }
         });
 
-        function setAsync<M extends RedisModules, S extends RedisScripts>(client: RedisClientType<M, S>, ...args: Array<string | Buffer | RedisCommandArguments>): Promise<RedisCommandRawReply> {
+        function setAsync<M extends RedisModules, S extends RedisScripts>(client: RedisClientType<M, S>, ...args: ClientLegacyCommandArguments): Promise<RedisCommandRawReply> {
             return new Promise((resolve, reject) => {
                 (client as any).set(...args, (err: Error | undefined, reply: RedisCommandRawReply) => {
                     if (err) return reject(err);
@@ -204,10 +204,10 @@ describe('Client', () => {
             }
         });
 
-        testUtils.testWithClient('client.{command} should accept mix of strings and array of strings', async client => {
+        testUtils.testWithClient('client.{command} should accept mix of arrays and arguments', async client => {
             assert.equal(
-                await setAsync(client, ['a'], 'b', ['XX']),
-                null
+                await setAsync(client, ['a'], 'b', ['EX', 1]),
+                'OK'
             );
         }, {
             ...GLOBAL.SERVERS.OPEN,
diff --git a/packages/client/lib/client/index.ts b/packages/client/lib/client/index.ts
index 40499cbf7c..dd1bf83334 100644
--- a/packages/client/lib/client/index.ts
+++ b/packages/client/lib/client/index.ts
@@ -9,7 +9,7 @@ import { CommandOptions, commandOptions, isCommandOptions } from '../command-opt
 import { ScanOptions, ZMember } from '../commands/generic-transformers';
 import { ScanCommandOptions } from '../commands/SCAN';
 import { HScanTuple } from '../commands/HSCAN';
-import { extendWithCommands, extendWithModulesAndScripts, transformCommandArguments, transformCommandReply } from '../commander';
+import { extendWithCommands, extendWithModulesAndScripts, LegacyCommandArguments, transformCommandArguments, transformCommandReply, transformLegacyCommandArguments } from '../commander';
 import { Pool, Options as PoolOptions, createPool } from 'generic-pool';
 import { ClientClosedError, DisconnectsClientError } from '../errors';
 import { URL } from 'url';
@@ -55,6 +55,7 @@ export interface ClientCommandOptions extends QueueCommandOptions {
 
 type ClientLegacyCallback = (err: Error | null, reply?: RedisCommandRawReply) => void;
 
+export type ClientLegacyCommandArguments = LegacyCommandArguments | [...LegacyCommandArguments, ClientLegacyCallback];
 export default class RedisClient<M extends RedisModules, S extends RedisScripts> extends EventEmitter {
     static commandOptions(options: ClientCommandOptions): CommandOptions<ClientCommandOptions> {
         return commandOptions(options);
@@ -246,12 +247,13 @@ export default class RedisClient<M extends RedisModules, S extends RedisScripts>
         if (!this.#options?.legacyMode) return;
 
         (this as any).#v4.sendCommand = this.#sendCommand.bind(this);
-        (this as any).sendCommand = (...args: Array<unknown>): void => {
-            const callback = typeof args[args.length - 1] === 'function' ?
-                    args[args.length - 1] as ClientLegacyCallback :
-                    undefined,
-                actualArgs = !callback ? args : args.slice(0, -1);
-            this.#sendCommand(actualArgs.flat() as Array<string>)
+        (this as any).sendCommand = (...args: ClientLegacyCommandArguments): void => {
+            let callback: ClientLegacyCallback;
+            if (typeof args[args.length - 1] === 'function') {
+                callback = args.pop() as ClientLegacyCallback;
+            }
+
+            this.#sendCommand(transformLegacyCommandArguments(args as LegacyCommandArguments))
                 .then((reply: RedisCommandRawReply) => {
                     if (!callback) return;
 
diff --git a/packages/client/lib/client/multi-command.ts b/packages/client/lib/client/multi-command.ts
index e4b2c165c8..9c19d3d068 100644
--- a/packages/client/lib/client/multi-command.ts
+++ b/packages/client/lib/client/multi-command.ts
@@ -1,7 +1,7 @@
 import COMMANDS from './commands';
 import { RedisCommand, RedisCommandArguments, RedisCommandRawReply, RedisModules, RedisPlugins, RedisScript, RedisScripts } from '../commands';
 import RedisMultiCommand, { RedisMultiQueuedCommand } from '../multi-command';
-import { extendWithCommands, extendWithModulesAndScripts } from '../commander';
+import { extendWithCommands, extendWithModulesAndScripts, LegacyCommandArguments, transformLegacyCommandArguments } from '../commander';
 
 type RedisClientMultiCommandSignature<C extends RedisCommand, M extends RedisModules, S extends RedisScripts> =
     (...args: Parameters<C['transformArguments']>) => RedisClientMultiCommandType<M, S>;
@@ -52,8 +52,8 @@ export default class RedisClientMultiCommand {
 
     #legacyMode(): void {
         this.v4.addCommand = this.addCommand.bind(this);
-        (this as any).addCommand = (...args: Array<string | Buffer | Array<string | Buffer>>): this => {
-            this.#multi.addCommand(args.flat());
+        (this as any).addCommand = (...args: LegacyCommandArguments): this => {
+            this.#multi.addCommand(transformLegacyCommandArguments(args));
             return this;
         };
         this.v4.exec = this.exec.bind(this);
diff --git a/packages/client/lib/commander.ts b/packages/client/lib/commander.ts
index 5871c2f235..50d416f5b5 100644
--- a/packages/client/lib/commander.ts
+++ b/packages/client/lib/commander.ts
@@ -113,3 +113,18 @@ export function transformCommandReply(
 
     return command.transformReply(rawReply, preserved);
 }
+
+export type LegacyCommandArguments = Array<string | number | Buffer | LegacyCommandArguments>;
+
+export function transformLegacyCommandArguments(args: LegacyCommandArguments, flat: RedisCommandArguments = []): RedisCommandArguments {
+    for (const arg of args) {
+        if (Array.isArray(arg)) {
+            transformLegacyCommandArguments(arg, flat);
+            continue;
+        }
+
+        flat.push(typeof arg === 'number' ? arg.toString() : arg);
+    }
+
+    return flat;
+}