diff --git a/.travis.yml b/.travis.yml
index cbe9517..de526eb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,3 @@
-dist: trusty
 language: php
 
 php:
@@ -6,7 +5,7 @@ php:
   - 7.2
 
 install:
-  - composer install --prefer-dist
+  - composer install
 
 script:
   - vendor/bin/phpunit
diff --git a/composer.json b/composer.json
index 288922e..892d93e 100644
--- a/composer.json
+++ b/composer.json
@@ -13,11 +13,16 @@
         "php": "^7.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "~7.0"
+        "phpunit/phpunit": "^7.0"
     },
     "autoload": {
         "files": ["src/bootstrap.php"]
     },
+    "autoload-dev": {
+        "psr-4": {
+            "iter\\": "test"
+        }
+    },
     "extra": {
         "branch-alias": {
             "dev-master": "2.0-dev"
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 0e317e9..cc14a19 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -9,7 +9,7 @@
          processIsolation="false"
          stopOnFailure="false"
          syntaxCheck="false"
-         bootstrap="./src/bootstrap.php">
+         bootstrap="./vendor/autoload.php">
     <testsuites>
         <testsuite name="Iter Test Suite">
             <directory>./test/</directory>
@@ -18,7 +18,10 @@
 
     <filter>
         <whitelist>
-            <directory suffix=".php">./lib/</directory>
+            <directory suffix=".php">src</directory>
+            <exclude>
+                <file suffix=".php">src/bootstrap.php</file>
+            </exclude>
         </whitelist>
     </filter>
-</phpunit>
\ No newline at end of file
+</phpunit>
diff --git a/src/bootstrap.php b/src/bootstrap.php
index 2bdb16f..61b3f2a 100644
--- a/src/bootstrap.php
+++ b/src/bootstrap.php
@@ -2,4 +2,4 @@
 
 require __DIR__ . '/iter.fn.php';
 require __DIR__ . '/iter.php';
-require __DIR__ . '/iter.rewindable.php';
\ No newline at end of file
+require __DIR__ . '/iter.rewindable.php';
diff --git a/test/MyIterator.php b/test/MyIterator.php
new file mode 100644
index 0000000..a2ca360
--- /dev/null
+++ b/test/MyIterator.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace iter;
+
+class MyIterator implements \Iterator {
+    private $position = 0;
+    private $array = [
+        "firstelement",
+        "secondelement",
+        "lastelement",
+    ];
+
+    public function __construct() {
+        $this->position = 0;
+    }
+
+    public function rewind() {
+        $this->position = 0;
+    }
+
+    public function current() {
+        return $this->array[$this->position];
+    }
+
+    public function key() {
+        return $this->position;
+    }
+
+    public function next() {
+        ++$this->position;
+    }
+
+    public function valid() {
+        return isset($this->array[$this->position]);
+    }
+}
diff --git a/test/MyIteratorAgg.php b/test/MyIteratorAgg.php
new file mode 100644
index 0000000..5bee9e8
--- /dev/null
+++ b/test/MyIteratorAgg.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace iter;
+
+class MyIteratorAgg implements \IteratorAggregate {
+    public $property1 = "Public property one";
+    public $property2 = "Public property two";
+    public $property3 = "Public property three";
+
+    public function __construct() {
+        $this->property4 = "last property";
+    }
+
+    public function getIterator() {
+        return new \ArrayIterator($this);
+    }
+}
diff --git a/test/iterTest.php b/test/iterTest.php
index e8311dc..dd0ec48 100644
--- a/test/iterTest.php
+++ b/test/iterTest.php
@@ -366,6 +366,11 @@ public function testIsEmpty() {
         $this->assertFalse(isEmpty(toArray([null])));
         $this->assertTrue(isEmpty(repeat(42, 0)));
         $this->assertFalse(isEmpty(repeat(42)));
+        $this->assertFalse(isEmpty(new MyIteratorAgg()));
+    }
+
+    public function testCountWithValidIteratorAgg() {
+        $this->assertSame(4, count(new MyIteratorAgg()));
     }
 
     public function testToArray() {