diff --git a/.travis.yml b/.travis.yml
index 2fbb9fc..7158ea9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,7 +10,6 @@ matrix:
   include:
     - php: 7.1
       env: DEPENDENCIES='low'
-    - php: 5.6
     - php: 7.0
     - php: 7.1
     - php: nightly
diff --git a/Bossa/PhpSpec/Expect/Subject.php b/Bossa/PhpSpec/Expect/Subject.php
index e0b524a..77efc7c 100644
--- a/Bossa/PhpSpec/Expect/Subject.php
+++ b/Bossa/PhpSpec/Expect/Subject.php
@@ -6,7 +6,7 @@
 
 class Subject extends BaseSubject
 {
-    public function __call($method, array $arguments = array())
+    public function __call(string $method, array $arguments = array())
     {
         if (preg_match('/^(to|notTo)(.+)$/', $method, $matches)) {
             $method = 'should'.$matches[2];
diff --git a/Bossa/PhpSpec/Expect/Wrapper.php b/Bossa/PhpSpec/Expect/Wrapper.php
index ccc5796..d3b3832 100644
--- a/Bossa/PhpSpec/Expect/Wrapper.php
+++ b/Bossa/PhpSpec/Expect/Wrapper.php
@@ -8,7 +8,7 @@
 use PhpSpec\Formatter\Presenter\Presenter;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use PhpSpec\Loader\Node\ExampleNode;
-
+use PhpSpec\Wrapper\Subject as BaseSubject;
 use PhpSpec\Wrapper\Subject\WrappedObject;
 use PhpSpec\Wrapper\Subject\Caller;
 use PhpSpec\Wrapper\Subject\SubjectWithArrayAccess;
@@ -33,7 +33,7 @@ public function __construct(MatcherManager $matchers, Presenter $presenter,
         $this->accessInspector = $accessInspector;
     }
 
-    public function wrap($value = null)
+    public function wrap($value = null): BaseSubject
     {
         $exceptionFactory   = new ExceptionFactory($this->presenter);
         $wrappedObject      = new WrappedObject($value, $this->presenter);
diff --git a/composer.json b/composer.json
index 28af3ee..6f26826 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
         }
     },
     "require": {
-        "phpspec/phpspec": "~3.2 <3.5.0"
+        "phpspec/phpspec": "^4.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^5.6|^6.0"