diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9a95411..c49fc43 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.3', '7.4']
+        php: ['7.3', '7.4', '8.0', '8.1']
     name: PHP ${{ matrix.php }}
     steps:
     - name: Checkout
@@ -26,7 +26,11 @@ jobs:
     - name: Install dependencies
       run: make vendor
     - name: Make
+      if: ${{ startsWith(matrix.php, '7.') }}
       run: make ci
+    - name: Make
+      if: ${{ startsWith(matrix.php, '8.') }}
+      run: make test
     - name: Upload coverage reports
       if: success()
       run: |
diff --git a/CHANGELOG.md b/CHANGELOG.md
index de1f064..726b51a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,12 @@
 # Phony for PHPUnit changelog
 
+## Next release
+
+This release uses *Phony* `5.x`. There no BC breaking API changes.
+
 ## 7.0.0 (2020-02-12)
 
+- **[BC BREAK]** PHP 7.2 is no longer supported.
 - **[BC BREAK]** Dropped support for PHPUnit `8.x`.
 - **[NEW]** Added support for PHPUnit `9.x`.
 
diff --git a/Makefile b/Makefile
index 3f9b56c..4fbb4d6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,9 @@
 # Powered by https://makefiles.dev/
 
+PHP_COMPOSER_INSTALL_ARGS += --ignore-platform-reqs
+
+################################################################################
+
 -include .makefiles/Makefile
 -include .makefiles/pkg/php/v1/Makefile
 
diff --git a/composer.json b/composer.json
index 53352b2..b183781 100644
--- a/composer.json
+++ b/composer.json
@@ -12,8 +12,8 @@
         }
     ],
     "require": {
-        "php": ">=7.3",
-        "eloquent/phony": "^4",
+        "php": "^7.3 || ^8",
+        "eloquent/phony": "^5",
         "phpunit/phpunit": "^9"
     },
     "require-dev": {
@@ -42,7 +42,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "6.1.x-dev"
+            "dev-master": "7.2.x-dev"
         }
     }
 }
diff --git a/test/suite/PhonyTest.php b/test/suite/PhonyTest.php
index 99dda77..95b4e95 100644
--- a/test/suite/PhonyTest.php
+++ b/test/suite/PhonyTest.php
@@ -274,7 +274,7 @@ public function testStubGlobal(): void
 
         $this->assertInstanceOf(StubVerifier::class, $actual);
         $this->assertSame('a, b', TestNamespace\sprintf('%s, %s', 'a', 'b'));
-        $this->assertNull(TestNamespace\sprintf('x', 'y'));
+        $this->assertEmpty(TestNamespace\sprintf('x', 'y'));
         $this->assertTrue((bool) $actual->calledWith('%s, %s', 'a', 'b'));
     }
 
@@ -285,7 +285,7 @@ public function testStubGlobalFunction(): void
 
         $this->assertInstanceOf(StubVerifier::class, $actual);
         $this->assertSame('a, b', TestNamespace\vsprintf('%s, %s', ['a', 'b']));
-        $this->assertNull(TestNamespace\vsprintf('x', 'y'));
+        $this->assertEmpty(TestNamespace\vsprintf('x', ['y']));
         $this->assertTrue((bool) $actual->calledWith('%s, %s', ['a', 'b']));
     }
 
@@ -294,8 +294,8 @@ public function testRestoreGlobalFunctions(): void
         Phony::stubGlobal('sprintf', TestNamespace::class);
         Phony::stubGlobal('vsprintf', TestNamespace::class);
 
-        $this->assertNull(TestNamespace\sprintf('%s, %s', 'a', 'b'));
-        $this->assertNull(TestNamespace\vsprintf('%s, %s', ['a', 'b']));
+        $this->assertEmpty(TestNamespace\sprintf('%s, %s', 'a', 'b'));
+        $this->assertEmpty(TestNamespace\vsprintf('%s, %s', ['a', 'b']));
 
         Phony::restoreGlobalFunctions();
 
@@ -308,8 +308,8 @@ public function testRestoreGlobalFunctionsFunction(): void
         stubGlobal('sprintf', TestNamespace::class);
         stubGlobal('vsprintf', TestNamespace::class);
 
-        $this->assertNull(TestNamespace\sprintf('%s, %s', 'a', 'b'));
-        $this->assertNull(TestNamespace\vsprintf('%s, %s', ['a', 'b']));
+        $this->assertEmpty(TestNamespace\sprintf('%s, %s', 'a', 'b'));
+        $this->assertEmpty(TestNamespace\vsprintf('%s, %s', ['a', 'b']));
 
         restoreGlobalFunctions();