diff --git a/.gitattributes b/.gitattributes
index aa522ca..b640645 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -3,4 +3,4 @@
 .gitignore export-ignore
 .travis.yml export-ignore
 build.xml export-ignore
-phpunit.xml export-ignore
+phpunit.xml.dist export-ignore
diff --git a/.gitignore b/.gitignore
index 05ab16b..50f8d9e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 build
 vendor
 composer.lock
+phpunit.xml
diff --git a/.travis.yml b/.travis.yml
index c775c11..56519fb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -33,7 +33,13 @@ cache:
     - $HOME/.composer/cache
 
 before_script:
-  - composer install --no-interaction --prefer-source
+  - |
+    if [[ $TRAVIS_PHP_VERSION != "nightly" ]]; then
+      composer install --no-suggest --no-interaction
+    else
+      # Ignore platform requirements to allow PHPUnit to install on PHP 8.
+      composer install --no-suggest --no-interaction --ignore-platform-reqs
+    fi
 
 script:
   - ant phplint
diff --git a/build.xml b/build.xml
index 6db22b7..9d95c2e 100644
--- a/build.xml
+++ b/build.xml
@@ -64,8 +64,8 @@
     <target name="phpunit" depends="prepare" description="PHP unit">
         <delete file="${basedir}/build/logs/phpunit.xml" quiet="true" />
 
-        <exec executable="${phpunit}">
-            <arg line='--configuration ${basedir}/phpunit.xml' />
+        <exec executable="${phpunit}" failonerror="true">
+            <arg line='--configuration ${basedir}/phpunit.xml.dist' />
             <arg line='-d memory_limit=256M' />
             <arg line='--log-junit "${basedir}/build/logs/phpunit.xml"' />
             <arg line='${colors-arg.color}' />
@@ -78,8 +78,8 @@
         <delete dir="${basedir}/build/coverage" quiet="true" />
         <mkdir dir="${basedir}/build/coverage" />
 
-        <exec executable="${phpunit}">
-            <arg line='--configuration ${basedir}/phpunit.xml' />
+        <exec executable="${phpunit}" failonerror="true">
+            <arg line='--configuration ${basedir}/phpunit.xml.dist' />
             <arg line='-d memory_limit=256M' />
             <arg line='--log-junit "${basedir}/build/logs/phpunit.xml"' />
             <arg line='--coverage-clover "${basedir}/build/logs/clover.xml"' />
diff --git a/composer.json b/composer.json
index b65462c..94aba0f 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         "php": ">=5.4.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~4.3",
+        "phpunit/phpunit": "^4.8.36 || ^5.0 || ^6.0 || ^7.0",
         "php-parallel-lint/php-parallel-lint": "^1.0",
         "php-parallel-lint/php-var-dump-check": "0.*",
         "squizlabs/php_codesniffer": "1.*",
diff --git a/phpunit.xml b/phpunit.xml.dist
similarity index 54%
rename from phpunit.xml
rename to phpunit.xml.dist
index f1105cc..c694fb2 100644
--- a/phpunit.xml
+++ b/phpunit.xml.dist
@@ -1,16 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
+    backupGlobals="true"
     bootstrap="./vendor/autoload.php">
+
     <testsuites>
-        <testsuite>
+        <testsuite name="PHP-Console-Color">
             <directory suffix="Test.php">tests</directory>
         </testsuite>
     </testsuites>
 
-    <!-- Ignore vendor folder for code coverage -->
     <filter>
-        <blacklist>
-            <directory>vendor</directory>
-        </blacklist>
+        <whitelist addUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
     </filter>
 </phpunit>
diff --git a/tests/ConsoleColorTest.php b/tests/ConsoleColorTest.php
index aaa1a22..f9a5398 100644
--- a/tests/ConsoleColorTest.php
+++ b/tests/ConsoleColorTest.php
@@ -1,5 +1,6 @@
 <?php
 use JakubOnderka\PhpConsoleColor\ConsoleColor;
+use PHPUnit\Framework\TestCase;
 
 class ConsoleColorWithForceSupport extends ConsoleColor
 {
@@ -28,7 +29,7 @@ public function are256ColorsSupported()
     }
 }
 
-class ConsoleColorTest extends \PHPUnit_Framework_TestCase
+class ConsoleColorTest extends TestCase
 {
     /** @var ConsoleColorWithForceSupport */
     private $uut;
@@ -41,13 +42,13 @@ protected function setUp()
     public function testNone()
     {
         $output = $this->uut->apply('none', 'text');
-        $this->assertEquals("text", $output);
+        $this->assertSame("text", $output);
     }
 
     public function testBold()
     {
         $output = $this->uut->apply('bold', 'text');
-        $this->assertEquals("\033[1mtext\033[0m", $output);
+        $this->assertSame("\033[1mtext\033[0m", $output);
     }
 
     public function testBoldColorsAreNotSupported()
@@ -55,7 +56,7 @@ public function testBoldColorsAreNotSupported()
         $this->uut->setIsSupported(false);
 
         $output = $this->uut->apply('bold', 'text');
-        $this->assertEquals("text", $output);
+        $this->assertSame("text", $output);
     }
 
     public function testBoldColorsAreNotSupportedButAreForced()
@@ -64,25 +65,25 @@ public function testBoldColorsAreNotSupportedButAreForced()
         $this->uut->setForceStyle(true);
 
         $output = $this->uut->apply('bold', 'text');
-        $this->assertEquals("\033[1mtext\033[0m", $output);
+        $this->assertSame("\033[1mtext\033[0m", $output);
     }
 
     public function testDark()
     {
         $output = $this->uut->apply('dark', 'text');
-        $this->assertEquals("\033[2mtext\033[0m", $output);
+        $this->assertSame("\033[2mtext\033[0m", $output);
     }
 
     public function testBoldAndDark()
     {
         $output = $this->uut->apply(array('bold', 'dark'), 'text');
-        $this->assertEquals("\033[1;2mtext\033[0m", $output);
+        $this->assertSame("\033[1;2mtext\033[0m", $output);
     }
 
     public function test256ColorForeground()
     {
         $output = $this->uut->apply('color_255', 'text');
-        $this->assertEquals("\033[38;5;255mtext\033[0m", $output);
+        $this->assertSame("\033[38;5;255mtext\033[0m", $output);
     }
 
     public function test256ColorWithoutSupport()
@@ -90,47 +91,47 @@ public function test256ColorWithoutSupport()
         $this->uut->setAre256ColorsSupported(false);
 
         $output = $this->uut->apply('color_255', 'text');
-        $this->assertEquals("text", $output);
+        $this->assertSame("text", $output);
     }
 
     public function test256ColorBackground()
     {
         $output = $this->uut->apply('bg_color_255', 'text');
-        $this->assertEquals("\033[48;5;255mtext\033[0m", $output);
+        $this->assertSame("\033[48;5;255mtext\033[0m", $output);
     }
 
     public function test256ColorForegroundAndBackground()
     {
         $output = $this->uut->apply(array('color_200', 'bg_color_255'), 'text');
-        $this->assertEquals("\033[38;5;200;48;5;255mtext\033[0m", $output);
+        $this->assertSame("\033[38;5;200;48;5;255mtext\033[0m", $output);
     }
 
     public function testSetOwnTheme()
     {
         $this->uut->setThemes(array('bold_dark' => array('bold', 'dark')));
         $output = $this->uut->apply(array('bold_dark'), 'text');
-        $this->assertEquals("\033[1;2mtext\033[0m", $output);
+        $this->assertSame("\033[1;2mtext\033[0m", $output);
     }
 
     public function testAddOwnTheme()
     {
         $this->uut->addTheme('bold_own', 'bold');
         $output = $this->uut->apply(array('bold_own'), 'text');
-        $this->assertEquals("\033[1mtext\033[0m", $output);
+        $this->assertSame("\033[1mtext\033[0m", $output);
     }
 
     public function testAddOwnThemeArray()
     {
         $this->uut->addTheme('bold_dark', array('bold', 'dark'));
         $output = $this->uut->apply(array('bold_dark'), 'text');
-        $this->assertEquals("\033[1;2mtext\033[0m", $output);
+        $this->assertSame("\033[1;2mtext\033[0m", $output);
     }
 
     public function testOwnWithStyle()
     {
         $this->uut->addTheme('bold_dark', array('bold', 'dark'));
         $output = $this->uut->apply(array('bold_dark', 'italic'), 'text');
-        $this->assertEquals("\033[1;2;3mtext\033[0m", $output);
+        $this->assertSame("\033[1;2;3mtext\033[0m", $output);
     }
 
     public function testHasAndRemoveTheme()
@@ -146,25 +147,25 @@ public function testHasAndRemoveTheme()
 
     public function testApplyInvalidArgument()
     {
-        $this->setExpectedException('\InvalidArgumentException');
+        $this->exceptionHelper('\InvalidArgumentException');
         $this->uut->apply(new stdClass(), 'text');
     }
 
     public function testApplyInvalidStyleName()
     {
-        $this->setExpectedException('\JakubOnderka\PhpConsoleColor\InvalidStyleException');
+        $this->exceptionHelper('\JakubOnderka\PhpConsoleColor\InvalidStyleException');
         $this->uut->apply('invalid', 'text');
     }
 
     public function testApplyInvalid256Color()
     {
-        $this->setExpectedException('\JakubOnderka\PhpConsoleColor\InvalidStyleException');
+        $this->exceptionHelper('\JakubOnderka\PhpConsoleColor\InvalidStyleException');
         $this->uut->apply('color_2134', 'text');
     }
 
     public function testThemeInvalidStyle()
     {
-        $this->setExpectedException('\JakubOnderka\PhpConsoleColor\InvalidStyleException');
+        $this->exceptionHelper('\JakubOnderka\PhpConsoleColor\InvalidStyleException');
         $this->uut->addTheme('invalid', array('invalid'));
     }
 
@@ -180,5 +181,23 @@ public function testGetPossibleStyles()
         $this->assertInternalType('array', $this->uut->getPossibleStyles());
         $this->assertNotEmpty($this->uut->getPossibleStyles());
     }
+
+    public function exceptionHelper($exception, $msg = null)
+    {
+        if (\method_exists($this, 'expectException')) {
+            // PHPUnit 5+.
+            $this->expectException($exception);
+            if (isset($msg)) {
+                $this->expectExceptionMessage($msg);
+            }
+        } else {
+            // PHPUnit 4.
+            if (isset($msg)) {
+                $this->setExpectedException($exception, $msg);
+            } else {
+                $this->setExpectedException($exception);
+            }
+        }
+    }
 }