diff --git a/.travis.yml b/.travis.yml
index 873079f..1f8db02 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,14 @@
 sudo: false
 language: php
 php:
+  - 7.1
   - 7.0
   - 5.6
   - 5.5
   - hhvm
+matrix:
+    allow_failures:
+        - php: hhvm
 before_script:
   - cp tests/config/config.travis-ci.php tests/config/config.php
   - composer install --dev
diff --git a/composer.json b/composer.json
index 7786424..e6163f0 100644
--- a/composer.json
+++ b/composer.json
@@ -24,14 +24,14 @@
         "issues": "https://github.com/RusticiSoftware/TinCanPHP/issues"
     },
     "require": {
-        "php": "~5.5 || ^7.0.3",
+        "php": "~5.5 || ^7.0 || ^7.1",
         "ext-openssl": "*",
         "namshi/jose": "^7.2.1",
         "willdurand/negotiation": "^2.0"
     },
     "require-dev": {
         "phpdocumentor/phpdocumentor": "2.*",
-        "phpunit/phpunit": "@stable"
+        "phpunit/phpunit": "^4.8 || ^5.6 || ^5.7"
     },
     "autoload": {
         "psr-4": {
diff --git a/tests/StatementTest.php b/tests/StatementTest.php
index ba04c09..af6b3d5 100644
--- a/tests/StatementTest.php
+++ b/tests/StatementTest.php
@@ -601,20 +601,46 @@ public function testHasAttachmentWithContent() {
     public function testSignNoArgs() {
         $obj = new Statement();
 
+        $expectedException = 'PHPUnit_Framework_Error_Warning';
+        $expectedMessage = 'Missing argument 1';
+
+        if (getenv('TRAVIS_PHP_VERSION') == "hhvm") {
+            $expectedMessage = "sign() expects at least 2 parameters, 0 given";
+        }
+
+        if (getenv('TRAVIS_PHP_VERSION') == "7.1") {
+            $expectedException = "ArgumentCountError";
+            $expectedMessage = "Too few arguments to function TinCan\Statement::sign(), 0 passed in /home/travis/build/RusticiSoftware/TinCanPHP/tests/StatementTest.php on line 621 and at least 2 expected";
+        }
+
         $this->setExpectedException(
-            'PHPUnit_Framework_Error_Warning',
-            (getenv('TRAVIS_PHP_VERSION') == "hhvm" ? 'sign() expects at least 2 parameters, 0 given' : 'Missing argument 1')
+            $expectedException,
+            $expectedMessage
         );
+
         $obj->sign();
     }
 
     public function testSignOneArg() {
         $obj = new Statement();
 
+        $expectedException = 'PHPUnit_Framework_Error_Warning';
+        $expectedMessage = 'Missing argument 2';
+
+        if (getenv('TRAVIS_PHP_VERSION') == "hhvm") {
+            $expectedMessage = "sign() expects at least 2 parameters, 1 given";
+        }
+
+        if (getenv('TRAVIS_PHP_VERSION') == "7.1") {
+            $expectedException = "ArgumentCountError";
+            $expectedMessage = "Too few arguments to function TinCan\Statement::sign(), 1 passed in /home/travis/build/RusticiSoftware/TinCanPHP/tests/StatementTest.php on line 644 and at least 2 expected";
+        }
+
         $this->setExpectedException(
-            'PHPUnit_Framework_Error_Warning',
-            (getenv('TRAVIS_PHP_VERSION') == "hhvm" ? 'sign() expects at least 2 parameters, 1 given' : 'Missing argument 2')
+            $expectedException,
+            $expectedMessage
         );
+
         $obj->sign('test');
     }