diff --git a/.github/workflows/it-tests.yml b/.github/workflows/it-tests.yml
index f8a6beb075..35b1eb92c4 100644
--- a/.github/workflows/it-tests.yml
+++ b/.github/workflows/it-tests.yml
@@ -51,7 +51,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        packageManager: [yarn, npm]
+        packageManager: [yarn, npm, yarn1]
         testEnvironment: [o3r-project-with-app]
     runs-on: ${{ matrix.os }}
     env:
diff --git a/packages/@o3r/create/src/index.ts b/packages/@o3r/create/src/index.ts
index 4a44cfef1b..454db6adf2 100644
--- a/packages/@o3r/create/src/index.ts
+++ b/packages/@o3r/create/src/index.ts
@@ -191,8 +191,7 @@ const addOtterFramework = (relativeDirectory = '.', projectPackageManager = 'npm
   const runner = process.platform === 'win32' ? `${projectPackageManager}.cmd` : projectPackageManager;
   const options = schematicsCliOptions
     .flat();
-
-  exitProcessIfErrorInSpawnSync(3, spawnSync(runner, ['exec', 'ng', 'add', `@o3r/core@~${version}`, ...(projectPackageManager === 'npm' ? ['--'] : []), ...options], {
+  exitProcessIfErrorInSpawnSync(3, spawnSync(runner, ['exec', 'ng', 'add', `@o3r/core@~${version}`, '--', ...options], {
     stdio: 'inherit',
     cwd
   }));
diff --git a/packages/@o3r/telemetry/src/environment/index.ts b/packages/@o3r/telemetry/src/environment/index.ts
index 56ca1b96e3..4369098933 100644
--- a/packages/@o3r/telemetry/src/environment/index.ts
+++ b/packages/@o3r/telemetry/src/environment/index.ts
@@ -4,14 +4,14 @@ import { execSync } from 'node:child_process';
 import * as path from 'node:path';
 
 /** Support NPM package managers */
-type SupportedPackageManagers = 'npm' | 'yarn';
+type SupportedPackageManagers = 'npm' | 'yarn' | 'yarn1';
 
 /**
  * Determine if the given packager manager is supported
  * @param name Name of the package manager
  */
 function isSupportedPackageManager(name?: any): name is SupportedPackageManagers {
-  return name === 'yarn' || name === 'npm';
+  return name in ['yarn', 'yarn1', 'npm'];
 }
 
 /**
@@ -19,7 +19,7 @@ function isSupportedPackageManager(name?: any): name is SupportedPackageManagers
  */
 function getPackageManager() {
   if (isSupportedPackageManager(process.env?.ENFORCED_PACKAGE_MANAGER)) {
-    return process.env.ENFORCED_PACKAGE_MANAGER;
+    return (process.env.ENFORCED_PACKAGE_MANAGE === 'npm') ? 'npm' : 'yarn';
   }
   return (process.env?.npm_execpath?.includes('yarn') && 'yarn') || 'npm';
 }
diff --git a/packages/@o3r/test-helpers/src/prepare-test-env.ts b/packages/@o3r/test-helpers/src/prepare-test-env.ts
index 854c09d39f..067fa99d40 100644
--- a/packages/@o3r/test-helpers/src/prepare-test-env.ts
+++ b/packages/@o3r/test-helpers/src/prepare-test-env.ts
@@ -3,7 +3,7 @@ import { cpSync, existsSync, mkdirSync, readdirSync, readFileSync, rmSync, statS
 import * as path from 'node:path';
 import type { PackageJson } from 'type-fest';
 import { createTestEnvironmentBlank } from './test-environments/create-test-environment-blank';
-import { createWithLock, getPackageManager, type Logger, packageManagerInstall, setPackagerManagerConfig, setupGit } from './utilities/index';
+import { createWithLock, getVersionedPackageManager, isYarn1, type Logger, packageManagerInstall, setPackagerManagerConfig, setupGit, YARN_1_LATEST_VERSION } from './utilities/index';
 import { createTestEnvironmentOtterProjectWithApp } from './test-environments/create-test-environment-otter-project';
 import { O3rCliError } from '@o3r/schematics';
 
@@ -15,8 +15,7 @@ export type PrepareTestEnvType = 'blank' | 'o3r-project-with-app';
 
 /**
  * Retrieve the version used by yarn and setup at root level
- * @param rootFolderPath: path to the folder where to take the configuration from
- * @param rootFolderPath
+ * @param rootFolderPath path to the folder where to take the configuration from
  */
 export function getYarnVersionFromRoot(rootFolderPath: string) {
   const o3rPackageJson: PackageJson & { generatorDependencies?: Record<string, string> } =
@@ -49,7 +48,7 @@ export async function prepareTestEnv(folderName: string, options?: PrepareTestEn
   const cacheFolderPath = path.resolve(globalFolderPath, 'cache');
 
   JSON.parse(readFileSync(path.join(rootFolderPath, 'packages', '@o3r', 'core', 'package.json')).toString());
-  const yarnVersion: string = yarnVersionParam || getYarnVersionFromRoot(rootFolderPath);
+  const yarnVersion: string = yarnVersionParam || (isYarn1() && YARN_1_LATEST_VERSION) || getYarnVersionFromRoot(rootFolderPath);
   const execAppOptions: ExecSyncOptions = {
     cwd: workspacePath,
     stdio: 'inherit',
@@ -108,7 +107,7 @@ export async function prepareTestEnv(folderName: string, options?: PrepareTestEn
   let isInWorkspace = false;
   let untouchedProject: undefined | string;
   let untouchedProjectPath: undefined | string;
-  const appDirectory = `${type}-${getPackageManager()}`;
+  const appDirectory = `${type}-${getVersionedPackageManager()}`;
   switch (type) {
     case 'blank': {
       await createTestEnvironmentBlank({
diff --git a/packages/@o3r/test-helpers/src/utilities/package-manager.ts b/packages/@o3r/test-helpers/src/utilities/package-manager.ts
index 02a1d82c90..3fab3fab0b 100644
--- a/packages/@o3r/test-helpers/src/utilities/package-manager.ts
+++ b/packages/@o3r/test-helpers/src/utilities/package-manager.ts
@@ -30,6 +30,15 @@ const PACKAGE_MANAGERS_CMD = {
     run: ['yarn', 'run'],
     workspaceExec: ['yarn', 'workspace'],
     workspaceRun: ['yarn', 'workspace']
+  },
+  yarn1: {
+    add: ['yarn', 'add'],
+    create: ['yarn', 'create'],
+    exec: ['yarn'],
+    install: ['yarn', 'install'],
+    run: ['yarn', 'run'],
+    workspaceExec: ['yarn', 'workspace'],
+    workspaceRun: ['yarn', 'workspace']
   }
 };
 
@@ -41,14 +50,36 @@ type CommandArguments = {
 };
 
 /**
- * Get the package manager to be used for the tests by reading environment variable ENFORCED_PACKAGE_MANAGER
+ * Get the package manager with its version to be used for the tests by reading environment variable ENFORCED_PACKAGE_MANAGER
+ * 'yarn', 'yarn1', 'npm'
  */
-export function getPackageManager() {
+export function getVersionedPackageManager() {
   return (process.env.ENFORCED_PACKAGE_MANAGER && process.env.ENFORCED_PACKAGE_MANAGER in PACKAGE_MANAGERS_CMD) ?
     process.env.ENFORCED_PACKAGE_MANAGER as keyof typeof PACKAGE_MANAGERS_CMD :
     'yarn';
 }
 
+/**
+ * Get the package manager to be used for the tests based on env ENFORCED_PACKAGE_MANAGER
+ * 'yarn', 'npm'
+ */
+export function getPackageManager() {
+  return getVersionedPackageManager() === 'npm' ? 'npm' : 'yarn';
+}
+
+
+/**
+ * latest version of yarn 1
+ */
+export const YARN_1_LATEST_VERSION = '1.22.19';
+
+/**
+ * is yarn 1
+ */
+export function isYarn1() {
+  return process.env.ENFORCED_PACKAGE_MANAGER === 'yarn1';
+}
+
 /**
  * Need to add additional dashes when running command like exec on npm
  * Convert `npm exec test --param` to `npm exec test -- --param`
@@ -90,7 +121,7 @@ function execCmd(args: string[], execOptions: ExecSyncOptions) {
  * @param options
  */
 export function packageManagerAdd(packages: string, options: ExecSyncOptions) {
-  return execCmd([...PACKAGE_MANAGERS_CMD[getPackageManager()].add, packages], options);
+  return execCmd([...PACKAGE_MANAGERS_CMD[getVersionedPackageManager()].add, packages], options);
 }
 
 /**
@@ -101,7 +132,7 @@ export function packageManagerAdd(packages: string, options: ExecSyncOptions) {
  */
 export function packageManagerCreate(command: CommandArguments, options: ExecSyncOptions, packageManagerOverride?: keyof typeof PACKAGE_MANAGERS_CMD) {
   const { script, args } = command;
-  const packageManager = packageManagerOverride || getPackageManager();
+  const packageManager = packageManagerOverride || getVersionedPackageManager();
   return execCmd([...PACKAGE_MANAGERS_CMD[packageManager].create, script, ...addDashesForNpmCommand(args, packageManager)], options);
 }
 
@@ -112,7 +143,7 @@ export function packageManagerCreate(command: CommandArguments, options: ExecSyn
  */
 export function packageManagerExec(command: CommandArguments, options: ExecSyncOptions) {
   const { script, args } = command;
-  return execCmd([...PACKAGE_MANAGERS_CMD[getPackageManager()].exec, script, ...addDashesForNpmCommand(args)], options);
+  return execCmd([...PACKAGE_MANAGERS_CMD[getVersionedPackageManager()].exec, script, ...addDashesForNpmCommand(args)], options);
 }
 
 /**
@@ -123,7 +154,7 @@ export function packageManagerExec(command: CommandArguments, options: ExecSyncO
  */
 export function packageManagerWorkspaceExec(workspaceProjectName: string, command: CommandArguments, options: ExecSyncOptions) {
   const { script, args } = command;
-  return execCmd([...PACKAGE_MANAGERS_CMD[getPackageManager()].workspaceExec, workspaceProjectName, script, ...addDashesForNpmCommand(args)], options);
+  return execCmd([...PACKAGE_MANAGERS_CMD[getVersionedPackageManager()].workspaceExec, workspaceProjectName, script, ...addDashesForNpmCommand(args)], options);
 }
 
 /**
@@ -142,7 +173,7 @@ export function packageManagerExecOnProject(projectName: string, isInWorkspace:
  * @param options
  */
 export function packageManagerInstall(options: ExecSyncOptions) {
-  return execCmd(PACKAGE_MANAGERS_CMD[getPackageManager()].install, options);
+  return execCmd(PACKAGE_MANAGERS_CMD[getVersionedPackageManager()].install, options);
 }
 
 /**
@@ -152,7 +183,7 @@ export function packageManagerInstall(options: ExecSyncOptions) {
  */
 export function packageManagerRun(command: CommandArguments, options: ExecSyncOptions) {
   const { script, args } = command;
-  return execCmd([...PACKAGE_MANAGERS_CMD[getPackageManager()].run, script, ...addDashesForNpmCommand(args)], options);
+  return execCmd([...PACKAGE_MANAGERS_CMD[getVersionedPackageManager()].run, script, ...addDashesForNpmCommand(args)], options);
 }
 
 /**
@@ -163,7 +194,7 @@ export function packageManagerRun(command: CommandArguments, options: ExecSyncOp
  */
 export function packageManagerWorkspaceRun(workspaceProjectName: string, command: CommandArguments, options: ExecSyncOptions) {
   const { script, args } = command;
-  return execCmd([...PACKAGE_MANAGERS_CMD[getPackageManager()].workspaceRun, workspaceProjectName, script, ...addDashesForNpmCommand(args)], options);
+  return execCmd([...PACKAGE_MANAGERS_CMD[getVersionedPackageManager()].workspaceRun, workspaceProjectName, script, ...addDashesForNpmCommand(args)], options);
 }
 
 /**
@@ -209,7 +240,7 @@ export function setPackagerManagerConfig(options: PackageManagerConfig, execAppO
 
   const packageJsonPath = join(execOptions.cwd as string, 'package.json');
   const shouldCleanPackageJson = !existsSync(packageJsonPath);
-  switch (getPackageManager()) {
+  switch (getVersionedPackageManager()) {
     case 'yarn': {
       // Set yarn version
       if (options.yarnVersion) {
@@ -231,6 +262,11 @@ export function setPackagerManagerConfig(options: PackageManagerConfig, execAppO
       execFileSync('yarn', ['config', 'set', 'unsafeHttpWhitelist', '127.0.0.1'], execOptions);
       break;
     }
+    case 'yarn1':{
+      if (options.yarnVersion) {
+        execFileSync('yarn', ['set', 'version', options.yarnVersion], execOptions);
+      }
+    }
   }
 
   execFileSync('npm', ['config', 'set', 'audit=false', '-L=project'], execOptions);