diff --git a/sandbox/src/index.ts b/sandbox/src/index.ts
index ac16deb..33f8af1 100644
--- a/sandbox/src/index.ts
+++ b/sandbox/src/index.ts
@@ -1,7 +1,7 @@
 import dotenv from 'dotenv';
 import fs from 'fs-extra';
 import urlJoin from 'url-join';
-import { string, z } from 'zod';
+import { z } from 'zod';
 import os, { EOL } from 'os';
 import { join } from 'path';
 import { simpleGit, SimpleGit } from 'simple-git';
@@ -90,12 +90,10 @@ async function cloneAndRun(submissionData: SubmissionGetData) {
 		return;
 	}
 	const tmpDir = os.tmpdir();
-	const buildDir = join(tmpDir, 'bwcontest-build');
-	if (fs.existsSync(buildDir)) {
-		fs.removeSync(buildDir);
+	const repoDir = join(tmpDir, 'bwcontest-src');
+	if (fs.existsSync(repoDir)) {
+		fs.removeSync(repoDir);
 	}
-	fs.mkdirSync(buildDir);
-	const repoDir = join(buildDir, 'src');
 	fs.mkdirSync(repoDir);
 
 	const teamRepoUrl = urlJoin(
@@ -114,7 +112,7 @@ async function cloneAndRun(submissionData: SubmissionGetData) {
 	try {
 		if (submissionData.submission.teamLanguage === 'Java') {
 			let res = await runJava({
-				srcDir: buildDir,
+				srcDir: repoDir,
 				mainFile: join(repoDir, problemName, problemName + '.java'),
 				mainClass: problemName,
 				input: submissionData.submission.problem.realInput
diff --git a/sandbox/src/run/cpp.ts b/sandbox/src/run/cpp.ts
index a4756fd..2db9403 100644
--- a/sandbox/src/run/cpp.ts
+++ b/sandbox/src/run/cpp.ts
@@ -4,6 +4,8 @@ import util from 'util';
 import { RunResult, timeoutSeconds } from '../index.js';
 import { IRunner, IRunnerParams, IRunnerReturn } from './types.js';
 import kill from 'tree-kill';
+import os from 'os';
+import fs from 'fs-extra';
 
 const execPromise = util.promisify(exec);
 
@@ -20,9 +22,16 @@ interface IRunnerParamsCpp extends IRunnerParams {
 export const runCpp: IRunner<IRunnerParamsCpp> = async function (
 	params: IRunnerParamsCpp
 ): IRunnerReturn {
+	const tmpDir = os.tmpdir();
+	const buildDir = join(tmpDir, 'bwcontest-cpp');
+	if (fs.existsSync(buildDir)) {
+		fs.removeSync(buildDir);
+	}
+	fs.mkdirSync(buildDir);
+
 	console.log(`- BUILD: ${params.problemName}`);
 
-	const configureCommand = `cmake -S ${params.srcDir} -B ${join(params.srcDir, 'build')}`;
+	const configureCommand = `cmake -S ${params.srcDir} -B ${buildDir}`;
 	try {
 		await execPromise(configureCommand);
 	} catch (e) {
@@ -34,7 +43,7 @@ export const runCpp: IRunner<IRunnerParamsCpp> = async function (
 		};
 	}
 
-	const compileCommand = `cmake --build ${join(params.srcDir, 'build')} --target ${params.problemName}`;
+	const compileCommand = `cmake --build ${buildDir} --target ${params.problemName}`;
 	try {
 		await execPromise(compileCommand);
 	} catch (e) {
@@ -50,9 +59,9 @@ export const runCpp: IRunner<IRunnerParamsCpp> = async function (
 
 	let runCommand = '';
 	if (params.cppPlatform === 'VisualStudio') {
-		runCommand = `${join(params.srcDir, 'build', 'Debug', `${params.problemName}.exe`)}`;
+		runCommand = `${join(buildDir, 'Debug', `${params.problemName}.exe`)}`;
 	} else {
-		runCommand = `${join(params.srcDir, 'build', params.problemName)}`;
+		runCommand = `${join(buildDir, params.problemName)}`;
 	}
 	try {
 		let outputBuffer = '';