diff --git a/.travis.yml b/.travis.yml
index de890615..86ddce95 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,23 +2,31 @@ language: php
 
 sudo: false
 
-dist: trusty
-
-php:
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7.0
-  - 7.1
-  - 7.2
-  - 7.3
-  - nightly
-  - hhvm
-
-matrix:
-    allow_failures:
-        - php: nightly
-        - php: hhvm
+jobs:
+  include:
+  - dist: trusty
+    php: 5.4
+  - dist: trusty
+    php: 5.5
+  - dist: xenial
+    php: 5.6
+  - dist: xenial
+    php: 7.0
+  - dist: xenial
+    php: 7.1
+  - dist: xenial
+    php: 7.2
+  - dist: xenial
+    php: 7.3
+  - dist: xenial
+    php: 7.4
+  - dist: xenial
+    php: nightly
+  - dist: xenial
+    php: hhvm
+  allow_failures:
+    - php: nightly
+    - php: hhvm
 
 before_script:
   - printf "\n" | pecl install imagick
diff --git a/composer.json b/composer.json
index f6240e04..e750b406 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
         "guzzlehttp/psr7": "~1.1 || ^2.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8 || ^5.7",
+        "phpunit/phpunit": "^4.8 || ^5.7 || ^7.5.15",
         "mockery/mockery": "~0.9.2"
     },
     "suggest": {
diff --git a/tests/FileTest.php b/tests/FileTest.php
index 820a18af..e1c01fd2 100644
--- a/tests/FileTest.php
+++ b/tests/FileTest.php
@@ -19,7 +19,7 @@ class FileTest extends TestCase
     public function testBasePath()
     {
         $file = new File;
-        $this->assertNull(null, $file->basePath());
+        $this->assertNull(null, $file->basePath() ?: '');
 
         $file->dirname = 'foo';
         $file->basename = 'bar';