diff --git a/composer.json b/composer.json
index 76ea46d..aad99dd 100644
--- a/composer.json
+++ b/composer.json
@@ -30,7 +30,7 @@
         "psr/http-server-middleware": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit" : "^7.0",
+        "phpunit/phpunit" : "^7.5",
         "phpstan/phpstan": "^0.12",
         "phpstan/phpstan-phpunit": "^0.12",
         "roave/security-advisories": "dev-master",
diff --git a/tests/RouteTest.php b/tests/RouteTest.php
index 42dc328..169f479 100644
--- a/tests/RouteTest.php
+++ b/tests/RouteTest.php
@@ -20,7 +20,7 @@ public function testRouteSetsAndResolvesInvokableClassCallable(): void
     {
         $callable = new Controller;
         $route    = new Route('GET', '/', $callable);
-        $this->assertInternalType('callable', $route->getCallable());
+        $this->assertIsCallable($route->getCallable());
     }
 
     /**
@@ -32,7 +32,7 @@ public function testRouteSetsAndResolvesClassMethodCallable(): void
     {
         $callable = [new Controller, 'action'];
         $route    = new Route('GET', '/', $callable);
-        $this->assertInternalType('callable', $route->getCallable());
+        $this->assertIsCallable($route->getCallable());
     }
 
     /**
@@ -44,7 +44,7 @@ public function testRouteSetsAndResolvesNamedFunctionCallable(): void
     {
         $callable = 'League\Route\Fixture\namedFunctionCallable';
         $route    = new Route('GET', '/', $callable);
-        $this->assertInternalType('callable', $route->getCallable());
+        $this->assertIsCallable($route->getCallable());
     }
 
     /**
diff --git a/tests/RouterTest.php b/tests/RouterTest.php
index ba13008..268afaa 100644
--- a/tests/RouterTest.php
+++ b/tests/RouterTest.php
@@ -89,7 +89,11 @@ public function testNewPatternMatchesCanBeAddedAtRuntime(): void
     {
         $router = new Router;
         $router->addPatternMatcher('mockMatcher', '[a-zA-Z]');
-        $matchers = $this->getObjectAttribute($router, 'patternMatchers');
+
+        $reflectionClass = new \ReflectionClass($router);
+        $reflectionProperty = $reflectionClass->getProperty('patternMatchers');
+        $reflectionProperty->setAccessible(true);
+        $matchers = $reflectionProperty->getValue($router);
 
         $this->assertArrayHasKey('/{(.+?):mockMatcher}/', $matchers);
         $this->assertEquals('{$1:[a-zA-Z]}', $matchers['/{(.+?):mockMatcher}/']);