diff --git a/.travis.yml b/.travis.yml
index 7c0d000..263792f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,16 +5,12 @@ dist: trusty
 matrix:
   fast_finish: true
   include:
-    - php: 7.1
-      env: LARAVEL=5.5.* ORCHESTRA=3.5.*
-    - php: 7.1
-      env: LARAVEL=5.6.* ORCHESTRA=3.6.*
     - php: 7.2
-      env: LARAVEL=5.7.* ORCHESTRA=3.7.*
+      env: LARAVEL=5.8.* ORCHESTRA=3.8.*
     - php: 7.2
-      env: LARAVEL=5.8.* ORCHESTRA=3.8.* COVERAGE=1
+      env: LARAVEL=6.0.* ORCHESTRA=4.0.* COVERAGE=1
     - php: 7.3
-      env: LARAVEL=5.8.* ORCHESTRA=3.8.*
+      env: LARAVEL=6.0.* ORCHESTRA=4.0.*
 
   allow_failures:
     - env: COVERAGE=1
diff --git a/composer.json b/composer.json
index 941f7fe..cbc1443 100644
--- a/composer.json
+++ b/composer.json
@@ -21,21 +21,21 @@
         "source": "https://github.com/richan-fongdasen/laravel-varnishable"
     },
     "require": {
-        "php": "^7.1.3",
+        "php": "^7.2",
         "guzzlehttp/guzzle": "~6.0",
-        "illuminate/database": "5.5.*|5.6.*|5.7.*|5.8.*",
-        "illuminate/support": "5.5.*|5.6.*|5.7.*|5.8.*"
+        "illuminate/database": "5.8.*|6.0.*",
+        "illuminate/support": "5.8.*|6.0.*"
     },
     "require-dev": {
         "mockery/mockery": "~1.0",
-        "orchestra/database": "~3.5",
-        "orchestra/testbench": "~3.5",
+        "orchestra/database": "~3.8|~4.0",
+        "orchestra/testbench": "~3.8|~4.0",
         "phpmd/phpmd": "^2.6",
-        "phpstan/phpstan": "^0.11.8",
+        "phpstan/phpstan": "^0.11.15",
         "phpstan/phpstan-deprecation-rules": "^0.11.2",
         "phpstan/phpstan-strict-rules": "^0.11.1",
-        "phpunit/phpunit": "^8.0 || ~7.0 || ~6.0",
-        "sebastian/phpcpd": "^4.1 || ~3.0"
+        "phpunit/phpunit": "^7.5|^8.0",
+        "sebastian/phpcpd": "^4.1"
     },
     "config": {
         "sort-packages": true
diff --git a/src/Concerns/ManageEtagHeader.php b/src/Concerns/ManageEtagHeader.php
index 4a14a3c..ffc5258 100644
--- a/src/Concerns/ManageEtagHeader.php
+++ b/src/Concerns/ManageEtagHeader.php
@@ -15,8 +15,11 @@ trait ManageEtagHeader
      */
     protected function addEtagHeader(Response $response) :void
     {
-        if ((bool) $this->getConfig('use_etag')) {
-            $response->setEtag(md5($response->getContent()));
+        $useEtag = (bool) $this->getConfig('use_etag');
+        $content = $response->getContent();
+
+        if (($content !== false) && $useEtag) {
+            $response->setEtag(md5($content));
         }
     }
 
diff --git a/tests/Supports/database/factories/UserFactory.php b/tests/Supports/database/factories/UserFactory.php
index a59d7e5..30ec5ab 100644
--- a/tests/Supports/database/factories/UserFactory.php
+++ b/tests/Supports/database/factories/UserFactory.php
@@ -1,5 +1,6 @@
 <?php
 
+use Illuminate\Support\Str;
 use RichanFongdasen\Varnishable\Tests\Supports\Models\User;
 
 $factory->define(User::class, function (\Faker\Generator $faker) {
@@ -8,8 +9,8 @@
     return [
         'name' => $faker->name,
         'email' => $faker->email,
-        'password' => bcrypt(str_random(12)),
-        'remember_token' => str_random(12),
+        'password' => bcrypt(Str::random(12)),
+        'remember_token' => Str::random(12),
         'created_at' => '2016-01-01 00:00:00',
         'updated_at' => date('Y-m-d H:i:s', $time),
     ];