diff --git a/packages/playwright-core/src/server/bidi/bidiFirefox.ts b/packages/playwright-core/src/server/bidi/bidiFirefox.ts
index 89bd962393752..a33d88dd34b35 100644
--- a/packages/playwright-core/src/server/bidi/bidiFirefox.ts
+++ b/packages/playwright-core/src/server/bidi/bidiFirefox.ts
@@ -57,6 +57,7 @@ export class BidiFirefox extends BrowserType {
       throw new Error(`Cannot launch Firefox with relative home directory. Did you set ${os.platform() === 'win32' ? 'USERPROFILE' : 'HOME'} to a relative path?`);
 
     env = {
+      'MOZ_DISABLE_SAFE_MODE_KEY': '1',
       ...env,
       'MOZ_CRASHREPORTER': '1',
       'MOZ_CRASHREPORTER_NO_REPORT': '1',
diff --git a/packages/playwright-core/src/server/firefox/firefox.ts b/packages/playwright-core/src/server/firefox/firefox.ts
index 3e0b505951500..b93f1fc773687 100644
--- a/packages/playwright-core/src/server/firefox/firefox.ts
+++ b/packages/playwright-core/src/server/firefox/firefox.ts
@@ -69,6 +69,10 @@ export class Firefox extends BrowserType {
   override amendEnvironment(env: NodeJS.ProcessEnv): NodeJS.ProcessEnv {
     if (!path.isAbsolute(os.homedir()))
       throw new Error(`Cannot launch Firefox with relative home directory. Did you set ${os.platform() === 'win32' ? 'USERPROFILE' : 'HOME'} to a relative path?`);
+    env = {
+      'MOZ_DISABLE_SAFE_MODE_KEY': '1',
+      ...env,
+    };
     if (os.platform() === 'linux') {
       // Always remove SNAP_NAME and SNAP_INSTANCE_NAME env variables since they
       // confuse Firefox: in our case, builds never come from SNAP.