<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Support\Facades\Redirect;
use Illuminate\Support\Facades\URL;

class EnsureEmailIsVerified
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @param  string|null  $redirectToRoute
     * @return \Illuminate\Http\Response|\Illuminate\Http\RedirectResponse|null
     */
    public function handle($request, Closure $next, $redirectToRoute = null)
    {
        if (! $request->user() ||
            ($request->user() instanceof MustVerifyEmail &&
            ! $request->user()->hasVerifiedEmail())
        ) {
            $params = [];
            if( env( 'SHOP_MULTILOCALE' ) ) {
                $params['locale'] = $request->route( 'locale', $request->input( 'locale', app()->getLocale() ) );
            }

            return $request->expectsJson()
                ? abort(403, 'Your email address is not verified.')
                : Redirect::guest(airoute($redirectToRoute ?: 'verification.notice', $params));
        }

        return $next($request);
    }
}
<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Support\Facades\Redirect;
use Illuminate\Support\Facades\URL;

class EnsureEmailIsVerified
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @param  string|null  $redirectToRoute
     * @return \Illuminate\Http\Response|\Illuminate\Http\RedirectResponse|null
     */
    public function handle($request, Closure $next, $redirectToRoute = null)
    {
        if (! $request->user() ||
            ($request->user() instanceof MustVerifyEmail &&
            ! $request->user()->hasVerifiedEmail())
        ) {
            $params = [];
            if( env( 'SHOP_MULTILOCALE' ) ) {
                $params['locale'] = $request->route( 'locale', $request->input( 'locale', app()->getLocale() ) );
            }
            return $request->expectsJson()
                ? abort(403, 'Your email address is not verified.')
                : Redirect::guest(URL::route($redirectToRoute ?: 'verification.notice', $params));
        }

        return $next($request);
    }
}
--- 
+++ 
@@ -27,9 +27,10 @@
             if( env( 'SHOP_MULTILOCALE' ) ) {
                 $params['locale'] = $request->route( 'locale', $request->input( 'locale', app()->getLocale() ) );
             }
+
             return $request->expectsJson()
                 ? abort(403, 'Your email address is not verified.')
-                : Redirect::guest(URL::route($redirectToRoute ?: 'verification.notice', $params));
+                : Redirect::guest(airoute($redirectToRoute ?: 'verification.notice', $params));
         }
 
         return $next($request);
Use airoute() to ensure redirect works correctly in multi-site setups
