diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ed3020b..651be1b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -34,7 +34,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
+        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
         min_stability: ['']
         name_suffix: ['']
         include:
diff --git a/composer.json b/composer.json
index a27bf91..873f852 100644
--- a/composer.json
+++ b/composer.json
@@ -12,9 +12,9 @@
         }
     ],
     "require": {
-        "php": "^7.3 || ^8",
-        "phpspec/prophecy": "^1.18",
-        "phpunit/phpunit":"^9.1 || ^10.1 || ^11.0"
+        "php": "^5.6 || ^7 || ^8",
+        "phpspec/prophecy": "^1.3",
+        "phpunit/phpunit": "^5.0 || ^6.0 || ^7.0 || ^8.0 || ^9.0 || ^10.0 || ^11.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/fixtures/SpyFailure.php b/fixtures/SpyFailure.php
index d7165c7..50c39b2 100644
--- a/fixtures/SpyFailure.php
+++ b/fixtures/SpyFailure.php
@@ -15,6 +15,7 @@ public function testMethod()
 
         $prophecy->reveal();
 
+        // Native PHPUnit implementation don't add this to the assertion count.
         $prophecy->format('Y-m-d')->shouldHaveBeenCalled();
     }
 }
diff --git a/src/ProphecyTrait.php b/src/ProphecyTrait.php
index db1676f..b0ba01a 100644
--- a/src/ProphecyTrait.php
+++ b/src/ProphecyTrait.php
@@ -1,125 +1,7 @@
-<?php declare(strict_types=1);
+<?php
 
-namespace Prophecy\PhpUnit;
-
-use PHPUnit\Framework\AssertionFailedError;
-use PHPUnit\Framework\Attributes\After;
-use PHPUnit\Framework\Attributes\PostCondition;
-use PHPUnit\Framework\TestCase;
-use Prophecy\Exception\Doubler\DoubleException;
-use Prophecy\Exception\Doubler\InterfaceNotFoundException;
-use Prophecy\Exception\Prediction\PredictionException;
-use Prophecy\Prophecy\MethodProphecy;
-use Prophecy\Prophecy\ObjectProphecy;
-use Prophecy\Prophet;
-
-/**
- * @mixin TestCase
- */
-trait ProphecyTrait
-{
-    /**
-     * @var Prophet|null
-     *
-     * @internal
-     */
-    private $prophet;
-
-    /**
-     * @var bool
-     *
-     * @internal
-     */
-    private $prophecyAssertionsCounted = false;
-
-    /**
-     * @throws DoubleException
-     * @throws InterfaceNotFoundException
-     *
-     * @template T of object
-     * @phpstan-param class-string<T>|null $classOrInterface
-     * @phpstan-return ($classOrInterface is null ? ObjectProphecy<object> : ObjectProphecy<T>)
-     *
-     * @not-deprecated
-     */
-    protected function prophesize(?string $classOrInterface = null): ObjectProphecy
-    {
-        static $isPhpUnit9;
-        $isPhpUnit9 = $isPhpUnit9 ?? method_exists($this, 'recordDoubledType');
-
-        if (! $isPhpUnit9) {
-            // PHPUnit 10.1
-            $this->registerFailureType(PredictionException::class);
-        } elseif (\is_string($classOrInterface)) {
-            // PHPUnit 9
-            \assert($this instanceof TestCase);
-            $this->recordDoubledType($classOrInterface);
-        }
-
-        return $this->getProphet()->prophesize($classOrInterface);
-    }
-
-    /**
-     * @postCondition
-     */
-    #[PostCondition]
-    protected function verifyProphecyDoubles(): void
-    {
-        if ($this->prophet === null) {
-            return;
-        }
-
-        try {
-            $this->prophet->checkPredictions();
-        } catch (PredictionException $e) {
-            throw new AssertionFailedError($e->getMessage());
-        } finally {
-            $this->countProphecyAssertions();
-        }
-    }
-
-    /**
-     * @after
-     */
-    #[After]
-    protected function tearDownProphecy(): void
-    {
-        if (null !== $this->prophet && !$this->prophecyAssertionsCounted) {
-            // Some Prophecy assertions may have been done in tests themselves even when a failure happened before checking mock objects.
-            $this->countProphecyAssertions();
-        }
-
-        $this->prophet = null;
-    }
-
-    /**
-     * @internal
-     */
-    private function countProphecyAssertions(): void
-    {
-        \assert($this instanceof TestCase);
-        $this->prophecyAssertionsCounted = true;
-
-        foreach ($this->prophet->getProphecies() as $objectProphecy) {
-            foreach ($objectProphecy->getMethodProphecies() as $methodProphecies) {
-                foreach ($methodProphecies as $methodProphecy) {
-                    \assert($methodProphecy instanceof MethodProphecy);
-
-                    $this->addToAssertionCount(\count($methodProphecy->getCheckedPredictions()));
-                }
-            }
-        }
-    }
-
-    /**
-     * @internal
-     */
-    private function getProphet(): Prophet
-    {
-        if ($this->prophet === null) {
-            $this->prophet = new Prophet;
-        }
-
-        return $this->prophet;
-    }
+if (PHP_VERSION_ID >= 70000) {
+    require_once __DIR__ . '/ProphecyTrait7.php';
+} else {
+    require_once __DIR__ . '/ProphecyTrait5.php';
 }
diff --git a/src/ProphecyTrait5.php b/src/ProphecyTrait5.php
new file mode 100644
index 0000000..7f42a1a
--- /dev/null
+++ b/src/ProphecyTrait5.php
@@ -0,0 +1,111 @@
+<?php
+
+namespace Prophecy\PhpUnit;
+
+use PHPUnit\Framework\AssertionFailedError;
+use PHPUnit\Framework\Attributes\After;
+use PHPUnit\Framework\TestCase;
+use Prophecy\Exception\Doubler\DoubleException;
+use Prophecy\Exception\Doubler\InterfaceNotFoundException;
+use Prophecy\Exception\Prediction\PredictionException;
+use Prophecy\Prophecy\MethodProphecy;
+use Prophecy\Prophecy\ObjectProphecy;
+use Prophecy\Prophet;
+
+/**
+ * @mixin TestCase
+ */
+trait ProphecyTrait
+{
+    /**
+     * @var Prophet|null
+     *
+     * @internal
+     */
+    private $prophet;
+
+    /**
+     * @throws DoubleException
+     * @throws InterfaceNotFoundException
+     *
+     * @template T of object
+     * @phpstan-param class-string<T>|null $classOrInterface
+     * @phpstan-return ($classOrInterface is null ? ObjectProphecy<object> : ObjectProphecy<T>)
+     *
+     * @not-deprecated
+     */
+    protected function prophesize($classOrInterface = null)
+    {
+        static $hasFailureTypes;
+
+        // PHPUnit 10.1.0+.
+        if ($hasFailureTypes === null) {
+            $hasFailureTypes = method_exists($this, 'registerFailureType');
+        }
+
+        if ($hasFailureTypes) {
+            $this->registerFailureType(PredictionException::class);
+        }
+
+        return $this->getProphet()->prophesize($classOrInterface);
+    }
+
+    /**
+     * @after
+     */
+    #[After]
+    protected function tearDownProphecy()
+    {
+        if (null !== $this->prophet) {
+            $this->verifyProphecyDoubles();
+        }
+
+        $this->prophet = null;
+    }
+
+    protected function verifyProphecyDoubles()
+    {
+        if ($this->prophet === null) {
+            return;
+        }
+
+        try {
+            $this->prophet->checkPredictions();
+        } catch (PredictionException $e) {
+            throw new AssertionFailedError($e->getMessage());
+        } finally {
+            // Some Prophecy assertions may have been done in tests themselves even when a failure happened before checking mock objects.
+            $this->countProphecyAssertions();
+        }
+    }
+
+    /**
+     * @internal
+     */
+    private function countProphecyAssertions()
+    {
+        \assert($this instanceof TestCase);
+
+        foreach ($this->prophet->getProphecies() as $objectProphecy) {
+            foreach ($objectProphecy->getMethodProphecies() as $methodProphecies) {
+                foreach ($methodProphecies as $methodProphecy) {
+                    \assert($methodProphecy instanceof MethodProphecy);
+
+                    $this->addToAssertionCount(\count($methodProphecy->getCheckedPredictions()));
+                }
+            }
+        }
+    }
+
+    /**
+     * @internal
+     */
+    private function getProphet()
+    {
+        if ($this->prophet === null) {
+            $this->prophet = new Prophet;
+        }
+
+        return $this->prophet;
+    }
+}
diff --git a/src/ProphecyTrait7.php b/src/ProphecyTrait7.php
new file mode 100644
index 0000000..e6beb23
--- /dev/null
+++ b/src/ProphecyTrait7.php
@@ -0,0 +1,111 @@
+<?php declare(strict_types=1);
+
+namespace Prophecy\PhpUnit;
+
+use PHPUnit\Framework\AssertionFailedError;
+use PHPUnit\Framework\Attributes\After;
+use PHPUnit\Framework\TestCase;
+use Prophecy\Exception\Doubler\DoubleException;
+use Prophecy\Exception\Doubler\InterfaceNotFoundException;
+use Prophecy\Exception\Prediction\PredictionException;
+use Prophecy\Prophecy\MethodProphecy;
+use Prophecy\Prophecy\ObjectProphecy;
+use Prophecy\Prophet;
+
+/**
+ * @mixin TestCase
+ */
+trait ProphecyTrait
+{
+    /**
+     * @var Prophet|null
+     *
+     * @internal
+     */
+    private $prophet;
+
+    /**
+     * @throws DoubleException
+     * @throws InterfaceNotFoundException
+     *
+     * @template T of object
+     * @phpstan-param class-string<T>|null $classOrInterface
+     * @phpstan-return ($classOrInterface is null ? ObjectProphecy<object> : ObjectProphecy<T>)
+     *
+     * @not-deprecated
+     */
+    protected function prophesize($classOrInterface = null): ObjectProphecy
+    {
+        static $hasFailureTypes;
+
+        // PHPUnit 10.1.0+.
+        if ($hasFailureTypes === null) {
+            $hasFailureTypes = method_exists($this, 'registerFailureType');
+        }
+
+        if ($hasFailureTypes) {
+            $this->registerFailureType(PredictionException::class);
+        }
+
+        return $this->getProphet()->prophesize($classOrInterface);
+    }
+
+    /**
+     * @after
+     */
+    #[After]
+    protected function tearDownProphecy()
+    {
+        if (null !== $this->prophet) {
+            $this->verifyProphecyDoubles();
+        }
+
+        $this->prophet = null;
+    }
+
+    protected function verifyProphecyDoubles()
+    {
+        if ($this->prophet === null) {
+            return;
+        }
+
+        try {
+            $this->prophet->checkPredictions();
+        } catch (PredictionException $e) {
+            throw new AssertionFailedError($e->getMessage());
+        } finally {
+            // Some Prophecy assertions may have been done in tests themselves even when a failure happened before checking mock objects.
+            $this->countProphecyAssertions();
+        }
+    }
+
+    /**
+     * @internal
+     */
+    private function countProphecyAssertions()/*: void*/
+    {
+        \assert($this instanceof TestCase);
+
+        foreach ($this->prophet->getProphecies() as $objectProphecy) {
+            foreach ($objectProphecy->getMethodProphecies() as $methodProphecies) {
+                foreach ($methodProphecies as $methodProphecy) {
+                    \assert($methodProphecy instanceof MethodProphecy);
+
+                    $this->addToAssertionCount(\count($methodProphecy->getCheckedPredictions()));
+                }
+            }
+        }
+    }
+
+    /**
+     * @internal
+     */
+    private function getProphet(): Prophet
+    {
+        if ($this->prophet === null) {
+            $this->prophet = new Prophet;
+        }
+
+        return $this->prophet;
+    }
+}
diff --git a/tests/MockFailure.phpt b/tests/MockFailure.phpt
index d5647ea..446f593 100644
--- a/tests/MockFailure.phpt
+++ b/tests/MockFailure.phpt
@@ -25,7 +25,8 @@ Double\DateTime\P1:
     but 1 were made:
       - format("Y-m-d") @ fixtures/MockFailure.php:%d
 
-%s/src/ProphecyTrait.php:%d
+%s/src/ProphecyTrait%d.php:%d
+%s/src/ProphecyTrait%d.php:%d
 %s/tests/run_test.php:%d
 
 FAILURES!
diff --git a/tests/run_test.php b/tests/run_test.php
index 5f1ec63..ff143e9 100644
--- a/tests/run_test.php
+++ b/tests/run_test.php
@@ -4,22 +4,26 @@
 
 use PHPUnit\TextUI\Application;
 use PHPUnit\TextUI\Command;
+use PHPUnit_TextUI_Command;
 
 require_once __DIR__ . '/xdebug_filter.php';
 require_once dirname(__DIR__) . '/vendor/autoload.php';
 
-function runTest(string $fixtureName): void
+function runTest($fixtureName)
 {
     $filename = dirname(__DIR__) . '/fixtures/' . $fixtureName . '.php';
     if (!file_exists($filename)) {
         throw new \InvalidArgumentException('Unable to find test fixture at path ' . $filename);
     }
 
-    if (class_exists(Command::class)) {
-        // PHPUnit 9.x
+    if (class_exists(Application::class)) {
+        // PHPUnit 10.x+.
+        (new Application())->run(['phpunit', $filename, '--no-configuration']);
+    } elseif (class_exists(Command::class)) {
+        // PHPUnit 9.x-.
         (new Command())->run(['phpunit', $filename, '--verbose', '--no-configuration'], false);
     } else {
-        // PHPUnit 10.x
-        (new Application())->run(['phpunit', $filename, '--no-configuration']);
+        // PHPUnit 5.x-.
+        (new PHPUnit_TextUI_Command())->run(['phpunit', $filename, '--verbose', '--no-configuration'], false);
     }
 }
diff --git a/tests/xdebug_filter.php b/tests/xdebug_filter.php
index 6e4279d..b939d6b 100644
--- a/tests/xdebug_filter.php
+++ b/tests/xdebug_filter.php
@@ -1,5 +1,9 @@
 <?php
-if (function_exists('xdebug_set_filter')) {
+if (function_exists('xdebug_set_filter')
+    && defined('XDEBUG_FILTER_CODE_COVERAGE')
+    && defined('XDEBUG_PATH_INCLUDE')
+    && defined('XDEBUG_PATH_EXCLUDE')
+) {
     xdebug_set_filter(
         XDEBUG_FILTER_CODE_COVERAGE,
         XDEBUG_PATH_INCLUDE,