diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..0a3b256
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,6 @@
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.travis.yml export-ignore
+/phpunit.xml export-ignore
+/phpunit-legacy.xml export-ignore
+/tests export-ignore
diff --git a/.travis.yml b/.travis.yml
index 30be35b..8d87e20 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,29 +1,27 @@
 language: php
 
-php:
-# - 5.3 # requires old distro, see below
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7.0
-  - 7.1
-  - 7.2
-  - hhvm # ignore errors, see below
-
 # lock distro so future defaults will not break the build
 dist: trusty
 
-matrix:
+jobs:
   include:
     - php: 5.3
       dist: precise
+    - php: 5.4
+    - php: 5.5
+    - php: 5.6
+    - php: 7.0
+    - php: 7.1
+    - php: 7.2
+    - php: 7.3
+    - php: 7.4
+    - php: hhvm-3.18
   allow_failures:
-    - php: hhvm
-
-sudo: false
+    - php: hhvm-3.18
 
 install:
-  - composer install --no-interaction
+  - composer install
 
 script:
-  - vendor/bin/phpunit --coverage-text
+  - if [[ "$TRAVIS_PHP_VERSION" > "7.2" ]]; then vendor/bin/phpunit --coverage-text; fi
+  - if [[ "$TRAVIS_PHP_VERSION" < "7.3" ]]; then vendor/bin/phpunit --coverage-text -c phpunit-legacy.xml; fi
diff --git a/composer.json b/composer.json
index 63f7db8..d9c6690 100644
--- a/composer.json
+++ b/composer.json
@@ -15,9 +15,12 @@
         "graphp/graph": "dev-master#fb198e4 as 1.0.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.4 || ^5.7 || ^4.8.35"
+        "phpunit/phpunit": "^9.3 || ^5.7 || ^4.8.35"
     },
     "autoload": {
         "psr-4": {"Graphp\\Algorithms\\": "src/"}
+    },
+    "autoload-dev": {
+        "psr-4": { "Graphp\\Tests\\Algorithms\\": "tests/" }
     }
 }
diff --git a/phpunit-legacy.xml b/phpunit-legacy.xml
new file mode 100644
index 0000000..91a3fef
--- /dev/null
+++ b/phpunit-legacy.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!-- PHPUnit configuration file with old format for PHPUnit 9.2 or older-->
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/4.8/phpunit.xsd"
+         bootstrap="vendor/autoload.php" 
+         colors="true">
+    <testsuites>
+        <testsuite name="Algorithm Test Suite">
+            <directory>./tests/</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist>
+            <directory>./src/</directory>
+        </whitelist>
+    </filter>
+</phpunit>
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..19452d4
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!-- PHPUnit configuration file with new format for PHPUnit 9.3+ -->
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+         bootstrap="vendor/autoload.php" 
+         colors="true" 
+         cacheResult="false">
+    <testsuites>
+        <testsuite name="Algorithm Test Suite">
+            <directory>./tests/</directory>
+        </testsuite>
+    </testsuites>
+    <coverage>
+        <include>
+            <directory>./src/</directory>
+        </include>
+    </coverage>
+</phpunit>
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
deleted file mode 100644
index 8748863..0000000
--- a/phpunit.xml.dist
+++ /dev/null
@@ -1,19 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-
-<phpunit bootstrap="tests/bootstrap.php"
-         colors="true"
-         convertErrorsToExceptions="true"
-         convertNoticesToExceptions="true"
-         convertWarningsToExceptions="true"
->
-    <testsuites>
-        <testsuite name="Algorithm Test Suite">
-            <directory>./tests/</directory>
-        </testsuite>
-    </testsuites>
-    <filter>
-        <whitelist>
-            <directory>./src/</directory>
-        </whitelist>
-    </filter>
-</phpunit>
\ No newline at end of file
diff --git a/tests/BipartitTest.php b/tests/BipartitTest.php
index 4534b0c..f8df8d4 100644
--- a/tests/BipartitTest.php
+++ b/tests/BipartitTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Bipartit as AlgorithmBipartit;
 use Graphp\Graph\Graph;
 
@@ -73,22 +75,22 @@ public function testGraphTriangleCycleIsNotBipartit()
     /**
      *
      * @param AlgorithmBipartit $alg
-     * @expectedException UnexpectedValueException
      * @depends testGraphTriangleCycleIsNotBipartit
      */
     public function testGraphTriangleCycleColorsInvalid(AlgorithmBipartit $alg)
     {
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getColors();
     }
 
     /**
      *
      * @param AlgorithmBipartit $alg
-     * @expectedException UnexpectedValueException
      * @depends testGraphTriangleCycleIsNotBipartit
      */
     public function testGraphTriangleCycleColorVerticesInvalid(AlgorithmBipartit $alg)
     {
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getColorVertices();
     }
 }
diff --git a/tests/CompleteTest.php b/tests/CompleteTest.php
index 4a2ce01..3282bed 100644
--- a/tests/CompleteTest.php
+++ b/tests/CompleteTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Complete as AlgorithmComplete;
 use Graphp\Graph\Graph;
 
diff --git a/tests/ConnectedComponentsTest.php b/tests/ConnectedComponentsTest.php
index 55f293d..8502964 100644
--- a/tests/ConnectedComponentsTest.php
+++ b/tests/ConnectedComponentsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\ConnectedComponents as AlgorithmConnected;
 use Graphp\Graph\Graph;
 
@@ -81,9 +83,6 @@ public function testComponents()
         $this->assertEquals($ge, $alg->createGraphComponentVertex($v5));
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testInvalidVertexPassedToAlgorithm()
     {
         $graph = new Graph();
@@ -92,6 +91,8 @@ public function testInvalidVertexPassedToAlgorithm()
         $v2 = $graph2->createVertex(12);
 
         $alg = new AlgorithmConnected($graph);
+
+        $this->setExpectedException('InvalidArgumentException');
         $alg->createGraphComponentVertex($v2);
     }
 }
diff --git a/tests/DegreeTest.php b/tests/DegreeTest.php
index 095ca5f..bf3c204 100644
--- a/tests/DegreeTest.php
+++ b/tests/DegreeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Degree as AlgorithmDegree;
 use Graphp\Graph\Exception\UnderflowException;
 use Graphp\Graph\Exception\UnexpectedValueException;
diff --git a/tests/DetectNegativeCycleTest.php b/tests/DetectNegativeCycleTest.php
index 3f90b09..afb676e 100644
--- a/tests/DetectNegativeCycleTest.php
+++ b/tests/DetectNegativeCycleTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\DetectNegativeCycle;
 use Graphp\Graph\Graph;
 
@@ -20,10 +22,10 @@ public function testNullGraph()
      *
      * @param DetectNegativeCycle $alg
      * @depends testNullGraph
-     * @expectedException UnderflowException
      */
     public function testNullGraphHasNoCycle(DetectNegativeCycle $alg)
     {
+        $this->setExpectedException('UnderflowException');
         $alg->getCycleNegative();
     }
 
@@ -31,10 +33,10 @@ public function testNullGraphHasNoCycle(DetectNegativeCycle $alg)
      *
      * @param DetectNegativeCycle $alg
      * @depends testNullGraph
-     * @expectedException UnderflowException
      */
     public function testNullGraphHasNoCycleGraph(DetectNegativeCycle $alg)
     {
+        $this->setExpectedException('UnderflowException');
         $alg->createGraph();
     }
 
diff --git a/tests/DirectedTest.php b/tests/DirectedTest.php
index 321f026..f3b1b94 100644
--- a/tests/DirectedTest.php
+++ b/tests/DirectedTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Directed as AlgorithmDirected;
 use Graphp\Graph\Graph;
 
diff --git a/tests/EulerianTest.php b/tests/EulerianTest.php
index 5ab2ec9..38838a9 100644
--- a/tests/EulerianTest.php
+++ b/tests/EulerianTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Eulerian as AlgorithmEulerian;
 use Graphp\Graph\Graph;
 
diff --git a/tests/FlowTest.php b/tests/FlowTest.php
index 7e2ebaf..3d50f46 100644
--- a/tests/FlowTest.php
+++ b/tests/FlowTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Flow as AlgorithmFlow;
 use Graphp\Graph\Graph;
 
@@ -24,7 +26,6 @@ public function testEdgeWithZeroFlowIsConsideredFlow()
         $graph = new Graph();
         $graph->createEdgeDirected($graph->createVertex(1), $graph->createVertex(2))->setFlow(0);
 
-
         $alg = new AlgorithmFlow($graph);
 
         $this->assertTrue($alg->hasFlow());
@@ -81,18 +82,15 @@ public function testGraphBalance()
         $this->assertFalse($alg->isBalancedFlow());
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testVertexWithUndirectedEdgeHasInvalidFlow()
     {
         // 1 -- 2
         $graph = new Graph();
         $graph->createEdgeUndirected($graph->createVertex(1), $graph->createVertex(2))->setFlow(10);
 
-
         $alg = new AlgorithmFlow($graph);
 
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getFlowVertex($graph->getVertex(1));
     }
 }
diff --git a/tests/GroupsTest.php b/tests/GroupsTest.php
index 5ee6311..89c0fdf 100644
--- a/tests/GroupsTest.php
+++ b/tests/GroupsTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Groups as AlgorithmGroups;
 use Graphp\Graph\Graph;
 
diff --git a/tests/LoopTest.php b/tests/LoopTest.php
index a9309b8..2933465 100644
--- a/tests/LoopTest.php
+++ b/tests/LoopTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Loop as AlgorithmLoop;
 use Graphp\Graph\Graph;
 
diff --git a/tests/MaxFlow/EdmondsKarpTest.php b/tests/MaxFlow/EdmondsKarpTest.php
index 7c93a1c..70b82cb 100644
--- a/tests/MaxFlow/EdmondsKarpTest.php
+++ b/tests/MaxFlow/EdmondsKarpTest.php
@@ -1,8 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MaxFlow;
+
 use Graphp\Algorithms\MaxFlow\EdmondsKarp as AlgorithmMaxFlowEdmondsKarp;
 use Graphp\Graph\Graph;
-use PHPUnit\Framework\TestCase;
+use Graphp\Tests\Algorithms\TestCase;
 
 class EdmondsKarpTest extends TestCase
 {
@@ -106,9 +108,6 @@ public function testEdgesMultiplePathsTree()
 //         $this->assertEquals(10, $alg->getFlowMax());
 //     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testEdgesUndirected()
     {
         // 0 -[0/7]- 1
@@ -121,6 +120,7 @@ public function testEdgesUndirected()
         // 0 -[7/7]- 1
         $alg = new AlgorithmMaxFlowEdmondsKarp($v0, $v1);
 
+        $this->setExpectedException('UnexpectedValueException');
         $this->assertEquals(7, $alg->getFlowMax());
     }
 
@@ -136,10 +136,6 @@ public function testEdgesUndirected()
 //         $this->assertEquals(0.735802, $alg->getFlowMax());
 //     }
 
-
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testInvalidFlowToOtherGraph()
     {
         $graph1 = new Graph();
@@ -148,17 +144,16 @@ public function testInvalidFlowToOtherGraph()
         $graph2 = new Graph();
         $vg2 = $graph2->createVertex(2);
 
+        $this->setExpectedException('InvalidArgumentException');
         new AlgorithmMaxFlowEdmondsKarp($vg1, $vg2);
     }
 
-    /**
-     * @expectedException InvalidArgumentException
-     */
     public function testInvalidFlowToSelf()
     {
         $graph = new Graph();
         $v1 = $graph->createVertex(1);
 
+        $this->setExpectedException('InvalidArgumentException');
         new AlgorithmMaxFlowEdmondsKarp($v1, $v1);
     }
 
diff --git a/tests/MaximumMatching/FlowTest.php b/tests/MaximumMatching/FlowTest.php
index 652fa53..d457ef0 100644
--- a/tests/MaximumMatching/FlowTest.php
+++ b/tests/MaximumMatching/FlowTest.php
@@ -1,8 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MaximumMatching;
+
 use Graphp\Algorithms\MaximumMatching\Flow;
 use Graphp\Graph\Graph;
-use PHPUnit\Framework\TestCase;
+use Graphp\Tests\Algorithms\TestCase;
 
 class FlowTest extends TestCase
 {
@@ -37,7 +39,6 @@ public function testSingleEdge()
 
     /**
      * expect exception for directed edges
-     * @expectedException UnexpectedValueException
      */
     public function testInvalidDirected()
     {
@@ -45,12 +46,13 @@ public function testInvalidDirected()
         $graph->createEdgeDirected($graph->createVertex(0)->setGroup(0), $graph->createVertex(1)->setGroup(1));
 
         $alg = new Flow($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getNumberOfMatches();
     }
 
     /**
      * expect exception for non-bipartit graphs
-     * @expectedException UnexpectedValueException
      */
     public function testInvalidBipartit()
     {
@@ -58,6 +60,8 @@ public function testInvalidBipartit()
         $graph->createEdgeUndirected($graph->createVertex(0)->setGroup(1), $graph->createVertex(1)->setGroup(1));
 
         $alg = new Flow($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getNumberOfMatches();
     }
 }
diff --git a/tests/MinimumCostFlow/BaseMcfTest.php b/tests/MinimumCostFlow/BaseMcfTest.php
index aef3aa5..35342c3 100644
--- a/tests/MinimumCostFlow/BaseMcfTest.php
+++ b/tests/MinimumCostFlow/BaseMcfTest.php
@@ -1,7 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MinimumCostFlow;
+
 use Graphp\Algorithms\MinimumCostFlow\Base;
 use Graphp\Graph\Graph;
+use Graphp\Tests\Algorithms\TestCase;
 
 abstract class BaseMcfTest extends TestCase
 {
@@ -112,9 +115,6 @@ public function testEdgeFlows()
         $this->assertEquals(14, $alg->getWeightFlow()); // 4*1 + 2*2 + 2*1 + 2*2
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testEdgeCapacityInsufficientFails()
     {
         // 1(+2) -[0/1]-> 2(-2)
@@ -124,12 +124,11 @@ public function testEdgeCapacityInsufficientFails()
         $graph->createEdgeDirected($v1, $v2)->setCapacity(1);
 
         $alg = $this->createAlgorithm($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getWeightFlow();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testEdgeCapacityUnsetFails()
     {
         // 1(+2) -> 2(-2)
@@ -139,12 +138,11 @@ public function testEdgeCapacityUnsetFails()
         $graph->createEdgeDirected($v1, $v2);
 
         $alg = $this->createAlgorithm($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getWeightFlow();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testIsolatedVerticesFail()
     {
         // 1(+2), 2(-2)
@@ -153,12 +151,11 @@ public function testIsolatedVerticesFail()
         $graph->createVertex(2)->setBalance(-2);
 
         $alg = $this->createAlgorithm($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getWeightFlow();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testUnbalancedFails()
     {
         // 1(+2) -> 2(-3)
@@ -168,12 +165,11 @@ public function testUnbalancedFails()
         $graph->createEdgeDirected($v1, $v2)->setCapacity(3);
 
         $alg = $this->createAlgorithm($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getWeightFlow();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testUndirectedFails()
     {
         // 1(+2) -- 2(-2)
@@ -183,12 +179,11 @@ public function testUndirectedFails()
         $graph->createEdgeUndirected($v1, $v2)->setCapacity(2);
 
         $alg = $this->createAlgorithm($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getWeightFlow();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testUndirectedNegativeCycleFails()
     {
         // 1(+2) -[0/2/-1]- 2(-2)
@@ -198,6 +193,8 @@ public function testUndirectedNegativeCycleFails()
         $graph->createEdgeUndirected($v1, $v2)->setCapacity(2)->setWeight(-1);
 
         $alg = $this->createAlgorithm($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getWeightFlow();
     }
 }
diff --git a/tests/MinimumCostFlow/CycleCancellingTest.php b/tests/MinimumCostFlow/CycleCancellingTest.php
index 841fc1a..62f45fc 100644
--- a/tests/MinimumCostFlow/CycleCancellingTest.php
+++ b/tests/MinimumCostFlow/CycleCancellingTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MinimumCostFlow;
+
 use Graphp\Algorithms\MinimumCostFlow\CycleCanceling;
 use Graphp\Graph\Graph;
 
diff --git a/tests/MinimumCostFlow/SuccessiveShortestPathTest.php b/tests/MinimumCostFlow/SuccessiveShortestPathTest.php
index ca441d4..054df58 100644
--- a/tests/MinimumCostFlow/SuccessiveShortestPathTest.php
+++ b/tests/MinimumCostFlow/SuccessiveShortestPathTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MinimumCostFlow;
+
 use Graphp\Algorithms\MinimumCostFlow\SuccessiveShortestPath;
 use Graphp\Graph\Graph;
 
diff --git a/tests/MinimumSpanningTree/BaseMstTest.php b/tests/MinimumSpanningTree/BaseMstTest.php
index b743b84..b963412 100644
--- a/tests/MinimumSpanningTree/BaseMstTest.php
+++ b/tests/MinimumSpanningTree/BaseMstTest.php
@@ -1,8 +1,11 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MinimumSpanningTree;
+
 use Graphp\Algorithms\MinimumSpanningTree\Base as MstBase;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
+use Graphp\Tests\Algorithms\TestCase;
 
 abstract class BaseMstTest extends TestCase
 {
@@ -131,9 +134,6 @@ public function testMixedGraphDirectionIsIgnored()
         $this->assertGraphEquals($graph, $alg->createGraph());
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testMultipleComponentsFail()
     {
         // 1 --[1]-- 2, 3 --[1]-- 4
@@ -146,12 +146,11 @@ public function testMultipleComponentsFail()
         $graph->createEdgeUndirected($v3, $v4)->setWeight(1);
 
         $alg = $this->createAlg($v1);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getEdges();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testMultipleIsolatedVerticesFormMultipleComponentsFail()
     {
         // 1, 2
@@ -160,6 +159,8 @@ public function testMultipleIsolatedVerticesFormMultipleComponentsFail()
         $graph->createVertex(2);
 
         $alg = $this->createAlg($v1);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getEdges();
     }
 
diff --git a/tests/MinimumSpanningTree/KruskalTest.php b/tests/MinimumSpanningTree/KruskalTest.php
index d145b78..9a4d53a 100644
--- a/tests/MinimumSpanningTree/KruskalTest.php
+++ b/tests/MinimumSpanningTree/KruskalTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MinimumSpanningTree;
+
 use Graphp\Algorithms\MinimumSpanningTree\Kruskal;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
@@ -11,14 +13,13 @@ protected function createAlg(Vertex $vertex)
         return new Kruskal($vertex->getGraph());
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testNullGraphIsNotConsideredToBeConnected()
     {
         $graph = new Graph();
 
         $alg = new Kruskal($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getEdges();
     }
 }
diff --git a/tests/MinimumSpanningTree/PrimTest.php b/tests/MinimumSpanningTree/PrimTest.php
index f860df7..5969ba0 100644
--- a/tests/MinimumSpanningTree/PrimTest.php
+++ b/tests/MinimumSpanningTree/PrimTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\MinimumSpanningTree;
+
 use Graphp\Algorithms\MinimumSpanningTree\Prim;
 use Graphp\Graph\Vertex;
 
diff --git a/tests/ParallelTest.php b/tests/ParallelTest.php
index 6698c08..0c4a1e4 100644
--- a/tests/ParallelTest.php
+++ b/tests/ParallelTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Parallel as AlgorithmParallel;
 use Graphp\Graph\Graph;
 
diff --git a/tests/Property/PropertyGraphTest.php b/tests/Property/PropertyGraphTest.php
index 8d9eb9b..d8f3125 100644
--- a/tests/Property/PropertyGraphTest.php
+++ b/tests/Property/PropertyGraphTest.php
@@ -1,7 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Property;
+
 use Graphp\Algorithms\Property\GraphProperty;
 use Graphp\Graph\Graph;
+use Graphp\Tests\Algorithms\TestCase;
 
 class PropertyGraphTest extends TestCase
 {
diff --git a/tests/Property/WalkPropertyTest.php b/tests/Property/WalkPropertyTest.php
index 62ea263..6438300 100644
--- a/tests/Property/WalkPropertyTest.php
+++ b/tests/Property/WalkPropertyTest.php
@@ -1,8 +1,11 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Property;
+
 use Graphp\Algorithms\Property\WalkProperty;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Walk;
+use Graphp\Tests\Algorithms\TestCase;
 
 class WalkPropertyTest extends TestCase
 {
diff --git a/tests/ResidualGraphTest.php b/tests/ResidualGraphTest.php
index d109e3a..05c3a79 100644
--- a/tests/ResidualGraphTest.php
+++ b/tests/ResidualGraphTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\ResidualGraph;
 use Graphp\Graph\Graph;
 
@@ -162,7 +164,6 @@ public function testParallelEdgesCanBeMerged()
 
     /**
      * expect exception for undirected edges
-     * @expectedException UnexpectedValueException
      */
     public function testInvalidUndirected()
     {
@@ -172,12 +173,13 @@ public function testInvalidUndirected()
                                                                   ->setCapacity(2);
 
         $alg = new ResidualGraph($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->createGraph();
     }
 
     /**
      * expect exception for edges with no flow
-     * @expectedException UnexpectedValueException
      */
     public function testInvalidNoFlow()
     {
@@ -186,12 +188,13 @@ public function testInvalidNoFlow()
         $graph->createEdgeDirected($graph->createVertex(), $graph->createVertex())->setCapacity(1);
 
         $alg = new ResidualGraph($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->createGraph();
     }
 
     /**
      * expect exception for edges with no capacity
-     * @expectedException UnexpectedValueException
      */
     public function testInvalidNoCapacity()
     {
@@ -200,6 +203,8 @@ public function testInvalidNoCapacity()
         $graph->createEdgeDirected($graph->createVertex(), $graph->createVertex())->setFlow(1);
 
         $alg = new ResidualGraph($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->createGraph();
     }
 
diff --git a/tests/Search/BreadthFirstTest.php b/tests/Search/BreadthFirstTest.php
index 6fba9da..62034c8 100644
--- a/tests/Search/BreadthFirstTest.php
+++ b/tests/Search/BreadthFirstTest.php
@@ -1,7 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Search;
+
 use Graphp\Algorithms\Search\BreadthFirst;
 use Graphp\Graph\Graph;
+use Graphp\Tests\Algorithms\TestCase;
 
 class BreadthFirstSearchTest extends TestCase
 {
diff --git a/tests/ShortestPath/BaseShortestPathTest.php b/tests/ShortestPath/BaseShortestPathTest.php
index a3844f3..ef4de7b 100644
--- a/tests/ShortestPath/BaseShortestPathTest.php
+++ b/tests/ShortestPath/BaseShortestPathTest.php
@@ -1,8 +1,11 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\ShortestPath;
+
 use Graphp\Algorithms\ShortestPath\Base as ShortestPathAlg;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
+use Graphp\Tests\Algorithms\TestCase;
 
 abstract class BaseShortestPathTest extends TestCase
 {
@@ -82,9 +85,6 @@ public function testGraphCycle()
         $this->assertEquals(2, \count($walk->getEdges()));
     }
 
-    /**
-     * @expectedException OutOfBoundsException
-     */
     public function testIsolatedVertexIsNotReachable()
     {
         // 1, 2
@@ -96,12 +96,10 @@ public function testIsolatedVertexIsNotReachable()
 
         $this->assertFalse($alg->hasVertex($v2));
 
+        $this->setExpectedException('OutOfBoundsException');
         $alg->getEdgesTo($v2);
     }
 
-    /**
-     * @expectedException OutOfBoundsException
-     */
     public function testSeparateGraphsAreNotReachable()
     {
         // 1
@@ -113,6 +111,7 @@ public function testSeparateGraphsAreNotReachable()
 
         $alg = $this->createAlg($vg1);
 
+        $this->setExpectedException('OutOfBoundsException');
         $alg->getEdgesTo($vg2);
     }
 
diff --git a/tests/ShortestPath/BreadthFirstTest.php b/tests/ShortestPath/BreadthFirstTest.php
index bc0d00a..cf723da 100644
--- a/tests/ShortestPath/BreadthFirstTest.php
+++ b/tests/ShortestPath/BreadthFirstTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\ShortestPath;
+
 use Graphp\Algorithms\ShortestPath\BreadthFirst;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
diff --git a/tests/ShortestPath/DijkstraTest.php b/tests/ShortestPath/DijkstraTest.php
index 7b7c9ef..b25eefb 100644
--- a/tests/ShortestPath/DijkstraTest.php
+++ b/tests/ShortestPath/DijkstraTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\ShortestPath;
+
 use Graphp\Algorithms\ShortestPath\Dijkstra;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
@@ -11,9 +13,6 @@ protected function createAlg(Vertex $vertex)
         return new Dijkstra($vertex);
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testGraphParallelNegative()
     {
         // 1 -[10]-> 2
@@ -27,6 +26,7 @@ public function testGraphParallelNegative()
 
         $alg = $this->createAlg($v1);
 
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getEdges();
     }
 }
diff --git a/tests/ShortestPath/MooreBellmanFordTest.php b/tests/ShortestPath/MooreBellmanFordTest.php
index 0fadcce..421e655 100644
--- a/tests/ShortestPath/MooreBellmanFordTest.php
+++ b/tests/ShortestPath/MooreBellmanFordTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\ShortestPath;
+
 use Graphp\Algorithms\ShortestPath\MooreBellmanFord;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
@@ -39,10 +41,10 @@ public function testGraphParallelNegative()
     /**
      * @param MooreBellmanFord $alg
      * @depends testGraphParallelNegative
-     * @expectedException UnderflowException
      */
     public function testNoNegativeCycle(MooreBellmanFord $alg)
     {
+        $this->setExpectedException('UnderflowException');
         $alg->getCycleNegative();
     }
 
@@ -96,16 +98,8 @@ public function testNegativeComponentHasCycle()
 
         // first component does not have a cycle
         $alg = $this->createAlg($v1);
-        $this->expectException('UnderflowException');
-        $alg->getCycleNegative();
-    }
 
-    public function expectException($class)
-    {
-        if (\method_exists($this, 'setExpectedException')) {
-            $this->setExpectedException($class);
-        } else {
-            parent::expectException($class);
-        }
+        $this->setExpectedException('UnderflowException');
+        $alg->getCycleNegative();
     }
 }
diff --git a/tests/SymmetricTest.php b/tests/SymmetricTest.php
index c1544cb..64ba0b5 100644
--- a/tests/SymmetricTest.php
+++ b/tests/SymmetricTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Symmetric as AlgorithmSymmetric;
 use Graphp\Graph\Graph;
 
diff --git a/tests/bootstrap.php b/tests/TestCase.php
similarity index 83%
rename from tests/bootstrap.php
rename to tests/TestCase.php
index 60b5908..513b52d 100644
--- a/tests/bootstrap.php
+++ b/tests/TestCase.php
@@ -1,13 +1,13 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Graph\Edge;
 use Graphp\Graph\EdgeDirected;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Vertex;
 use PHPUnit\Framework\TestCase as BaseTestCase;
 
-(include_once __DIR__ . '/../vendor/autoload.php') OR die(PHP_EOL . 'ERROR: composer autoloader not found, run "composer install" or see README for instructions' . PHP_EOL);
-
 class TestCase extends BaseTestCase
 {
     protected function assertGraphEquals(Graph $expected, Graph $actual)
@@ -95,4 +95,21 @@ private function getEdgeDump(Edge $edge)
 
         return $ret;
     }
+
+    public function setExpectedException($exception, $exceptionMessage = '', $exceptionCode = null)
+    {
+        if (method_exists($this, 'expectException')) {
+            // PHPUnit 6+
+            $this->expectException($exception);
+            if ($exceptionMessage !== '') {
+                $this->expectExceptionMessage($exceptionMessage);
+            }
+            if ($exceptionCode !== null) {
+                $this->expectExceptionCode($exceptionCode);
+            }
+        } else {
+            // legacy PHPUnit 4 - PHPUnit 5
+            parent::setExpectedException($exception, $exceptionMessage, $exceptionCode);
+        }
+    }
 }
diff --git a/tests/TopologicalSortTest.php b/tests/TopologicalSortTest.php
index ce5e3c4..bfa0909 100644
--- a/tests/TopologicalSortTest.php
+++ b/tests/TopologicalSortTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\TopologicalSort;
 use Graphp\Graph\Graph;
 
@@ -36,33 +38,28 @@ public function testGraphSimple()
         $this->assertSame(array($graph->getVertex(1), $graph->getVertex(2)), $alg->getVertices()->getVector());
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testFailUndirected()
     {
         $graph = new Graph();
         $graph->createEdgeUndirected($graph->createVertex(1), $graph->createVertex(2));
 
         $alg = new TopologicalSort($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getVertices();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testFailLoop()
     {
         $graph = new Graph();
         $graph->createEdgeDirected($graph->createVertex(1), $graph->getVertex(1));
 
         $alg = new TopologicalSort($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getVertices();
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testFailCycle()
     {
         $graph = new Graph();
@@ -70,6 +67,8 @@ public function testFailCycle()
         $graph->createEdgeDirected($graph->getVertex(2), $graph->getVertex(1));
 
         $alg = new TopologicalSort($graph);
+
+        $this->setExpectedException('UnexpectedValueException');
         $alg->getVertices();
     }
 }
diff --git a/tests/TravelingSalesmanProblem/BruteforceTest.php b/tests/TravelingSalesmanProblem/BruteforceTest.php
index bb43e3c..41c10e5 100644
--- a/tests/TravelingSalesmanProblem/BruteforceTest.php
+++ b/tests/TravelingSalesmanProblem/BruteforceTest.php
@@ -1,7 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\TravelingSalesmanProblem;
+
 use Graphp\Algorithms\TravelingSalesmanProblem\Bruteforce;
 use Graphp\Graph\Graph;
+use Graphp\Tests\Algorithms\TestCase;
 
 class BruteforceTest extends TestCase
 {
@@ -33,7 +36,7 @@ public function testSetUpperLimitMstSetsExactLimitForSimpleCycle()
         $alg = new Bruteforce($graph);
         $alg->setUpperLimitMst();
 
-        $ref = new ReflectionProperty($alg, 'upperLimit');
+        $ref = new \ReflectionProperty($alg, 'upperLimit');
         $ref->setAccessible(true);
 
         $this->assertEquals(6, $ref->getValue($alg));
diff --git a/tests/Tree/BaseDirectedTest.php b/tests/Tree/BaseDirectedTest.php
index 4713392..804e5a4 100644
--- a/tests/Tree/BaseDirectedTest.php
+++ b/tests/Tree/BaseDirectedTest.php
@@ -1,8 +1,11 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Tree;
+
 use Graphp\Algorithms\Tree\BaseDirected;
 use Graphp\Graph\Graph;
 use Graphp\Graph\Set\Vertices;
+use Graphp\Tests\Algorithms\TestCase;
 
 abstract class BaseDirectedTest extends TestCase
 {
@@ -43,30 +46,30 @@ public function testNullGraph()
     /**
      * @param BaseDirected $tree
      * @depends testNullGraph
-     * @expectedException UnderflowException
      */
     public function testEmptyGraphDoesNotHaveRootVertex(BaseDirected $tree)
     {
+        $this->setExpectedException('UnderflowException');
         $tree->getVertexRoot();
     }
 
     /**
      * @param BaseDirected $tree
      * @depends testNullGraph
-     * @expectedException UnderflowException
      */
     public function testEmptyGraphDoesNotHaveDegree(BaseDirected $tree)
     {
+        $this->setExpectedException('UnderflowException');
         $tree->getDegree();
     }
 
     /**
      * @param BaseDirected $tree
      * @depends testNullGraph
-     * @expectedException UnderflowException
      */
     public function testEmptyGraphDoesNotHaveHeight(BaseDirected $tree)
     {
+        $this->setExpectedException('UnderflowException');
         $tree->getHeight();
     }
 
@@ -108,11 +111,12 @@ public function testGraphTree()
      *
      * @param BaseDirected $tree
      * @depends testGraphTree
-     * @expectedException UnderflowException
      */
     public function testGraphTreeRootDoesNotHaveParent(BaseDirected $tree)
     {
         $root = $tree->getVertexRoot();
+
+        $this->setExpectedException('UnderflowException');
         $tree->getVertexParent($root);
     }
 
@@ -125,15 +129,13 @@ public function testNonTree()
         $this->assertFalse($tree->isTree());
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testNonTreeVertexHasMoreThanOneParent()
     {
         $graph = $this->createGraphNonTree();
 
         $tree = $this->createTreeAlg($graph);
 
+        $this->setExpectedException('UnexpectedValueException');
         $tree->getVertexParent($graph->getVertex('v3'));
     }
 
@@ -157,9 +159,6 @@ public function testGraphWithLoopIsNotTree()
         $this->assertFalse($tree->isTree());
     }
 
-    /**
-     * @expectedException UnexpectedValueException
-     */
     public function testGraphWithLoopCanNotGetSubgraph()
     {
         // v1 -> v1
@@ -168,6 +167,7 @@ public function testGraphWithLoopCanNotGetSubgraph()
 
         $tree = $this->createTreeAlg($graph);
 
+        $this->setExpectedException('UnexpectedValueException');
         $tree->getVerticesSubtree($graph->getVertex('v1'));
     }
 
diff --git a/tests/Tree/InTreeTest.php b/tests/Tree/InTreeTest.php
index 3d05496..eec4a13 100644
--- a/tests/Tree/InTreeTest.php
+++ b/tests/Tree/InTreeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Tree;
+
 use Graphp\Algorithms\Tree\InTree;
 use Graphp\Graph\Graph;
 
diff --git a/tests/Tree/OutTreeTest.php b/tests/Tree/OutTreeTest.php
index af973a0..28bdcd3 100644
--- a/tests/Tree/OutTreeTest.php
+++ b/tests/Tree/OutTreeTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Tree;
+
 use Graphp\Algorithms\Tree\OutTree;
 use Graphp\Graph\Graph;
 
diff --git a/tests/Tree/UndirectedTest.php b/tests/Tree/UndirectedTest.php
index 1306c9e..8f99f3f 100644
--- a/tests/Tree/UndirectedTest.php
+++ b/tests/Tree/UndirectedTest.php
@@ -1,7 +1,10 @@
 <?php
 
+namespace Graphp\Tests\Algorithms\Tree;
+
 use Graphp\Algorithms\Tree\Undirected;
 use Graphp\Graph\Graph;
+use Graphp\Tests\Algorithms\TestCase;
 
 class UndirectedTest extends TestCase
 {
diff --git a/tests/WeightTest.php b/tests/WeightTest.php
index b20375d..a38379e 100644
--- a/tests/WeightTest.php
+++ b/tests/WeightTest.php
@@ -1,5 +1,7 @@
 <?php
 
+namespace Graphp\Tests\Algorithms;
+
 use Graphp\Algorithms\Weight as AlgorithmWeight;
 use Graphp\Graph\Graph;