diff --git a/tests/integration/DocblocksWithAnnotationsTest.php b/tests/integration/DocblocksWithAnnotationsTest.php
index 9864643..ffd9c42 100644
--- a/tests/integration/DocblocksWithAnnotationsTest.php
+++ b/tests/integration/DocblocksWithAnnotationsTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/integration/InterpretingDocBlocksTest.php b/tests/integration/InterpretingDocBlocksTest.php
index ce91d38..531422e 100644
--- a/tests/integration/InterpretingDocBlocksTest.php
+++ b/tests/integration/InterpretingDocBlocksTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/integration/ReconstitutingADocBlockTest.php b/tests/integration/ReconstitutingADocBlockTest.php
index d411bb4..23f54c8 100644
--- a/tests/integration/ReconstitutingADocBlockTest.php
+++ b/tests/integration/ReconstitutingADocBlockTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/integration/UsingTagsTest.php b/tests/integration/UsingTagsTest.php
index a6b9467..ec886a1 100644
--- a/tests/integration/UsingTagsTest.php
+++ b/tests/integration/UsingTagsTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/DescriptionFactoryTest.php b/tests/unit/DocBlock/DescriptionFactoryTest.php
index ca92701..9a758e8 100644
--- a/tests/unit/DocBlock/DescriptionFactoryTest.php
+++ b/tests/unit/DocBlock/DescriptionFactoryTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/DescriptionTest.php b/tests/unit/DocBlock/DescriptionTest.php
index 30fd0a8..7df5659 100644
--- a/tests/unit/DocBlock/DescriptionTest.php
+++ b/tests/unit/DocBlock/DescriptionTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
@@ -124,13 +125,4 @@ class DescriptionTest extends TestCase
         $expected = '@JoinTable(name="table", joinColumns={@JoinColumn (name="column_id", referencedColumnName="id")}, inverseJoinColumns={@JoinColumn (name="column_id_2", referencedColumnName="id")})';
         $this->assertSame($expected, (string)$fixture);
     }
-
-    /**
-     * @covers ::__construct
-     * @expectedException \InvalidArgumentException
-     */
-    public function testBodyTemplateMustBeAString()
-    {
-        new Description([]);
-    }
 }
diff --git a/tests/unit/DocBlock/ExampleFinderTest.php b/tests/unit/DocBlock/ExampleFinderTest.php
index 7c306fa..78e81df 100644
--- a/tests/unit/DocBlock/ExampleFinderTest.php
+++ b/tests/unit/DocBlock/ExampleFinderTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 namespace phpDocumentor\Reflection\DocBlock;
 
diff --git a/tests/unit/DocBlock/SerializerTest.php b/tests/unit/DocBlock/SerializerTest.php
index 69a164a..5e6caaa 100644
--- a/tests/unit/DocBlock/SerializerTest.php
+++ b/tests/unit/DocBlock/SerializerTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
@@ -198,40 +199,4 @@ DOCCOMMENT_AFTER_REMOVE;
         $docBlock->removeTag($genericTag);
         $this->assertSame($expectedAfterRemove, $fixture->getDocComment($docBlock));
     }
-
-    /**
-     * @covers ::__construct
-     * @expectedException \InvalidArgumentException
-     */
-    public function testInitializationFailsIfIndentIsNotAnInteger()
-    {
-        new Serializer([]);
-    }
-
-    /**
-     * @covers ::__construct
-     * @expectedException \InvalidArgumentException
-     */
-    public function testInitializationFailsIfIndentStringIsNotAString()
-    {
-        new Serializer(0, []);
-    }
-
-    /**
-     * @covers ::__construct
-     * @expectedException \InvalidArgumentException
-     */
-    public function testInitializationFailsIfIndentFirstLineIsNotABoolean()
-    {
-        new Serializer(0, '', []);
-    }
-
-    /**
-     * @covers ::__construct
-     * @expectedException \InvalidArgumentException
-     */
-    public function testInitializationFailsIfLineLengthIsNotNullNorAnInteger()
-    {
-        new Serializer(0, '', false, []);
-    }
 }
diff --git a/tests/unit/DocBlock/StandardTagFactoryTest.php b/tests/unit/DocBlock/StandardTagFactoryTest.php
index 13d60e9..a181e65 100644
--- a/tests/unit/DocBlock/StandardTagFactoryTest.php
+++ b/tests/unit/DocBlock/StandardTagFactoryTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/AuthorTest.php b/tests/unit/DocBlock/Tags/AuthorTest.php
index ea0d099..0d43bb9 100644
--- a/tests/unit/DocBlock/Tags/AuthorTest.php
+++ b/tests/unit/DocBlock/Tags/AuthorTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/CoversTest.php b/tests/unit/DocBlock/Tags/CoversTest.php
index 2750420..101157b 100644
--- a/tests/unit/DocBlock/Tags/CoversTest.php
+++ b/tests/unit/DocBlock/Tags/CoversTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/DeprecatedTest.php b/tests/unit/DocBlock/Tags/DeprecatedTest.php
index 3fc3df2..2e7ef92 100644
--- a/tests/unit/DocBlock/Tags/DeprecatedTest.php
+++ b/tests/unit/DocBlock/Tags/DeprecatedTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/ExampleTest.php b/tests/unit/DocBlock/Tags/ExampleTest.php
index 1d9207f..49bdad1 100644
--- a/tests/unit/DocBlock/Tags/ExampleTest.php
+++ b/tests/unit/DocBlock/Tags/ExampleTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 namespace DocBlock\Tags;
 
diff --git a/tests/unit/DocBlock/Tags/Formatter/AlignFormatterTest.php b/tests/unit/DocBlock/Tags/Formatter/AlignFormatterTest.php
index 1a4fbb3..b5eab3a 100644
--- a/tests/unit/DocBlock/Tags/Formatter/AlignFormatterTest.php
+++ b/tests/unit/DocBlock/Tags/Formatter/AlignFormatterTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/Formatter/PassthroughFormatterTest.php b/tests/unit/DocBlock/Tags/Formatter/PassthroughFormatterTest.php
index cb2009e..6fa8055 100644
--- a/tests/unit/DocBlock/Tags/Formatter/PassthroughFormatterTest.php
+++ b/tests/unit/DocBlock/Tags/Formatter/PassthroughFormatterTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/GenericTest.php b/tests/unit/DocBlock/Tags/GenericTest.php
index 62d37c0..fbfd64b 100644
--- a/tests/unit/DocBlock/Tags/GenericTest.php
+++ b/tests/unit/DocBlock/Tags/GenericTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/LinkTest.php b/tests/unit/DocBlock/Tags/LinkTest.php
index 8e26758..c6d1cb6 100644
--- a/tests/unit/DocBlock/Tags/LinkTest.php
+++ b/tests/unit/DocBlock/Tags/LinkTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/MethodTest.php b/tests/unit/DocBlock/Tags/MethodTest.php
index c7e6700..d9d31a1 100644
--- a/tests/unit/DocBlock/Tags/MethodTest.php
+++ b/tests/unit/DocBlock/Tags/MethodTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
@@ -347,10 +348,10 @@ class MethodTest extends TestCase
      * @param string null $expectedKeyType
      */
     public function testCollectionReturnTypes(
-        $returnType,
-        $expectedType,
-        $expectedValueType = null,
-        $expectedKeyType = null
+        string $returnType,
+        string $expectedType,
+        string $expectedValueType = null,
+        string $expectedKeyType = null
     ) {
         $resolver           = new TypeResolver();
         $descriptionFactory = m::mock(DescriptionFactory::class);
diff --git a/tests/unit/DocBlock/Tags/ParamTest.php b/tests/unit/DocBlock/Tags/ParamTest.php
index 17737ab..d1ee0e5 100644
--- a/tests/unit/DocBlock/Tags/ParamTest.php
+++ b/tests/unit/DocBlock/Tags/ParamTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/PropertyReadTest.php b/tests/unit/DocBlock/Tags/PropertyReadTest.php
index 003bb4c..c14543d 100644
--- a/tests/unit/DocBlock/Tags/PropertyReadTest.php
+++ b/tests/unit/DocBlock/Tags/PropertyReadTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/PropertyTest.php b/tests/unit/DocBlock/Tags/PropertyTest.php
index 90f69d8..3ad6cca 100644
--- a/tests/unit/DocBlock/Tags/PropertyTest.php
+++ b/tests/unit/DocBlock/Tags/PropertyTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/PropertyWriteTest.php b/tests/unit/DocBlock/Tags/PropertyWriteTest.php
index 96fbfef..7051d79 100644
--- a/tests/unit/DocBlock/Tags/PropertyWriteTest.php
+++ b/tests/unit/DocBlock/Tags/PropertyWriteTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/ReturnTest.php b/tests/unit/DocBlock/Tags/ReturnTest.php
index 335cd5e..0a97829 100644
--- a/tests/unit/DocBlock/Tags/ReturnTest.php
+++ b/tests/unit/DocBlock/Tags/ReturnTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/SeeTest.php b/tests/unit/DocBlock/Tags/SeeTest.php
index ae4fa53..9f3c21e 100644
--- a/tests/unit/DocBlock/Tags/SeeTest.php
+++ b/tests/unit/DocBlock/Tags/SeeTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/SinceTest.php b/tests/unit/DocBlock/Tags/SinceTest.php
index 778c0d7..985b325 100644
--- a/tests/unit/DocBlock/Tags/SinceTest.php
+++ b/tests/unit/DocBlock/Tags/SinceTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/SourceTest.php b/tests/unit/DocBlock/Tags/SourceTest.php
index 810607d..289b757 100644
--- a/tests/unit/DocBlock/Tags/SourceTest.php
+++ b/tests/unit/DocBlock/Tags/SourceTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/ThrowsTest.php b/tests/unit/DocBlock/Tags/ThrowsTest.php
index 5747e8f..3adf2bb 100644
--- a/tests/unit/DocBlock/Tags/ThrowsTest.php
+++ b/tests/unit/DocBlock/Tags/ThrowsTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/UsesTest.php b/tests/unit/DocBlock/Tags/UsesTest.php
index 02ec763..30c27cb 100644
--- a/tests/unit/DocBlock/Tags/UsesTest.php
+++ b/tests/unit/DocBlock/Tags/UsesTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/VarTest.php b/tests/unit/DocBlock/Tags/VarTest.php
index 49a72ef..57de21e 100644
--- a/tests/unit/DocBlock/Tags/VarTest.php
+++ b/tests/unit/DocBlock/Tags/VarTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlock/Tags/VersionTest.php b/tests/unit/DocBlock/Tags/VersionTest.php
index 4ccc159..562d315 100644
--- a/tests/unit/DocBlock/Tags/VersionTest.php
+++ b/tests/unit/DocBlock/Tags/VersionTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlockFactoryTest.php b/tests/unit/DocBlockFactoryTest.php
index 4bb91ad..85be2a1 100644
--- a/tests/unit/DocBlockFactoryTest.php
+++ b/tests/unit/DocBlockFactoryTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *
diff --git a/tests/unit/DocBlockTest.php b/tests/unit/DocBlockTest.php
index ca1edc5..3ea7e23 100644
--- a/tests/unit/DocBlockTest.php
+++ b/tests/unit/DocBlockTest.php
@@ -1,4 +1,5 @@
-<?php
+<?php declare(strict_types=1);
+
 /**
  * This file is part of phpDocumentor.
  *