diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 366d72a..dc9cf4b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,6 +11,7 @@ jobs:
     strategy:
       matrix:
         php:
+          - 8.0
           - 7.4
           - 7.3
           - 7.2
@@ -41,7 +42,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: shivammathur/setup-php@v2
         with:
-          php-version: 7.4
+          php-version: 8.0
           coverage: xdebug
       - run: composer install
       - run: vendor/bin/phpunit --coverage-text
diff --git a/README.md b/README.md
index 2ec6219..a0f3ebb 100644
--- a/README.md
+++ b/README.md
@@ -1185,7 +1185,7 @@ $ composer require react/stream:^1.1.1
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
 
 This project aims to run on any platform and thus does not require any PHP
-extensions and supports running on legacy PHP 5.3 through current PHP 7+ and HHVM.
+extensions and supports running on legacy PHP 5.3 through current PHP 8+ and HHVM.
 It's *highly recommended to use PHP 7+* for this project due to its vast
 performance improvements.
 
diff --git a/tests/TestCase.php b/tests/TestCase.php
index 7bef2f5..af07e3e 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -86,4 +86,15 @@ public function assertContainsStringIgnoringCase($needle, $haystack)
             $this->assertContains($needle, $haystack, '', true);
         }
     }
+
+    public function assertSameIgnoringCase($expected, $actual)
+    {
+        if (method_exists($this, 'assertEqualsIgnoringCase')) {
+            // PHPUnit 7.5+
+            $this->assertEqualsIgnoringCase($expected, $actual);
+        } else {
+            // legacy PHPUnit 4 - PHPUnit 7.5
+            $this->assertSame($expected, $actual);
+        }
+    }
 }
diff --git a/tests/WritableResourceStreamTest.php b/tests/WritableResourceStreamTest.php
index 7b36418..f0a3b42 100644
--- a/tests/WritableResourceStreamTest.php
+++ b/tests/WritableResourceStreamTest.php
@@ -485,7 +485,7 @@ public function testWritingToClosedStream()
         $buffer->handleWrite();
 
         $this->assertInstanceOf('Exception', $error);
-        $this->assertSame('Unable to write to stream: fwrite(): send of 3 bytes failed with errno=32 Broken pipe', $error->getMessage());
+        $this->assertSameIgnoringCase('Unable to write to stream: fwrite(): send of 3 bytes failed with errno=32 Broken pipe', $error->getMessage());
     }
 
     private function createWriteableLoopMock()