diff --git a/src/Builder.php b/src/Builder.php
index 1da80f2..007323a 100644
--- a/src/Builder.php
+++ b/src/Builder.php
@@ -31,9 +31,9 @@ class Builder
 
         $xml = collect($this->filters)->map(function ($items) {
             return $this->buildEntry($items);
-        })->implode('');
+        })->implode(PHP_EOL);
 
-        return $prefix . $xml . $suffix;
+        return collect([$prefix, $xml, $suffix])->implode(PHP_EOL);
     }
 
     /**
diff --git a/tests/Unit/BuilderTest.php b/tests/Unit/BuilderTest.php
index 40cac6c..a5f6029 100644
--- a/tests/Unit/BuilderTest.php
+++ b/tests/Unit/BuilderTest.php
@@ -20,20 +20,13 @@ class BuilderTest extends TestCase
 
         $result = new Builder([$filterA, $filterB]);
 
-        $expected = "<?xml version='1.0' encoding='UTF-8'?>";
-        $expected .= "<feed xmlns='http://www.w3.org/2005/Atom' xmlns:apps='http://schemas.google.com/apps/2006'>";
-        $expected .= '<entry>';
-        $expected .= "<apps:property name='from' value='foo@example.com|test@example.com'/>";
-        $expected .= "<apps:property name='label' value='Some label'/>";
-        $expected .= "<apps:property name='shouldArchive' value='true'/>";
-        $expected .= '</entry>';
-        $expected .= '<entry>';
-        $expected .= "<apps:property name='hasTheWord' value='from:bar@example.com'/>";
-        $expected .= "<apps:property name='shouldStar' value='true'/>";
-        $expected .= "<apps:property name='shouldAlwaysMarkAsImportant' value='true'/>";
-        $expected .= '</entry>';
-        $expected .= '</feed>';
+        $expected = <<<EOF
+<?xml version='1.0' encoding='UTF-8'?><feed xmlns='http://www.w3.org/2005/Atom' xmlns:apps='http://schemas.google.com/apps/2006'>
+<entry><apps:property name='from' value='foo@example.com|test@example.com'/><apps:property name='label' value='Some label'/><apps:property name='shouldArchive' value='true'/></entry>
+<entry><apps:property name='hasTheWord' value='from:bar@example.com'/><apps:property name='shouldStar' value='true'/><apps:property name='shouldAlwaysMarkAsImportant' value='true'/></entry>
+</feed>
+EOF;
 
-        $this->assertEquals($expected, $result);
+        $this->assertEquals($expected, $result->__toString());
     }
 }