diff --git a/.travis.yml b/.travis.yml
index 9cd7032..5fd9922 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,6 +9,7 @@ php:
   - 7.1
   - 7.2
   - 7.3
+  - 7.4
   - hhvm # ignore errors, see below
 
 # lock distro so new future defaults will not break the build
@@ -25,4 +26,5 @@ install:
   - composer install --no-interaction
 
 script:
-  - vendor/bin/phpunit --coverage-text
+  - ./vendor/bin/phpunit -v
+  - ./vendor/bin/phpunit -v --coverage-text --coverage-clover=./build/logs/clover.xml
diff --git a/composer.json b/composer.json
index 1fdaddd..cfe99ee 100644
--- a/composer.json
+++ b/composer.json
@@ -23,6 +23,6 @@
         "react/promise": "^2.7.0 || ^1.2.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6.4 || ^5.7 || ^4.8.35"
+        "phpunit/phpunit": "^7.0 || ^6.4 || ^5.7 || ^4.8.35"
     }
 }
diff --git a/tests/FunctionRejectTest.php b/tests/FunctionRejectTest.php
index dbbff3d..30d42de 100644
--- a/tests/FunctionRejectTest.php
+++ b/tests/FunctionRejectTest.php
@@ -53,6 +53,10 @@ public function testWaitingForPromiseToRejectDoesNotLeaveGarbageCycles()
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = Timer\reject(0.01, $this->loop);
@@ -68,6 +72,10 @@ public function testCancellingPromiseDoesNotLeaveGarbageCycles()
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = Timer\reject(0.01, $this->loop);
diff --git a/tests/FunctionResolveTest.php b/tests/FunctionResolveTest.php
index c4e2be7..155e82b 100644
--- a/tests/FunctionResolveTest.php
+++ b/tests/FunctionResolveTest.php
@@ -75,6 +75,10 @@ public function testWaitingForPromiseToResolveDoesNotLeaveGarbageCycles()
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = Timer\resolve(0.01, $this->loop);
@@ -90,6 +94,10 @@ public function testCancellingPromiseDoesNotLeaveGarbageCycles()
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = Timer\resolve(0.01, $this->loop);
diff --git a/tests/FunctionTimeoutTest.php b/tests/FunctionTimeoutTest.php
index 9652d1a..0c7378d 100644
--- a/tests/FunctionTimeoutTest.php
+++ b/tests/FunctionTimeoutTest.php
@@ -176,6 +176,10 @@ public function testWaitingForPromiseToResolveBeforeTimeoutDoesNotLeaveGarbageCy
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = Timer\resolve(0.01, $this->loop);
@@ -194,6 +198,10 @@ public function testWaitingForPromiseToRejectBeforeTimeoutDoesNotLeaveGarbageCyc
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = Timer\reject(0.01, $this->loop);
@@ -212,6 +220,10 @@ public function testWaitingForPromiseToTimeoutDoesNotLeaveGarbageCycles()
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = new \React\Promise\Promise(function () { }, function () {
@@ -232,6 +244,10 @@ public function testWaitingForPromiseToTimeoutWithoutCancellerDoesNotLeaveGarbag
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = new \React\Promise\Promise(function () { });
@@ -250,6 +266,10 @@ public function testWaitingForPromiseToTimeoutWithNoOpCancellerDoesNotLeaveGarba
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = new \React\Promise\Promise(function () { }, function () {
@@ -270,6 +290,10 @@ public function testCancellingPromiseDoesNotLeaveGarbageCycles()
             $this->markTestSkipped('Not supported on legacy Promise v1 API');
         }
 
+        if ($this->getTestResultObject()->getCollectCodeCoverageInformation() === true) {
+            $this->markTestSkipped('This test has memory leaks when code coverage is collected');
+        }
+
         gc_collect_cycles();
 
         $promise = new \React\Promise\Promise(function () { }, function () {