diff --git a/ChangeLog-10.1.md b/ChangeLog-10.1.md
index fdee9eb79..33b77792d 100644
--- a/ChangeLog-10.1.md
+++ b/ChangeLog-10.1.md
@@ -2,6 +2,12 @@
 
 All notable changes are documented in this file using the [Keep a CHANGELOG](http://keepachangelog.com/) principles.
 
+## [10.1.5] - 2023-MM-DD
+
+### Changed
+
+* [#1011](https://github.com/sebastianbergmann/php-code-coverage/pull/1011): Avoid serialization of cache data in PHP report
+
 ## [10.1.4] - 2023-08-31
 
 ### Fixed
@@ -41,6 +47,7 @@ All notable changes are documented in this file using the [Keep a CHANGELOG](htt
 
 * The `SebastianBergmann\CodeCoverage\Filter::includeDirectory()`, `SebastianBergmann\CodeCoverage\Filter::excludeDirectory()`, and `SebastianBergmann\CodeCoverage\Filter::excludeFile()` methods are now deprecated
 
+[10.1.5]: https://github.com/sebastianbergmann/php-code-coverage/compare/10.1.4...main
 [10.1.4]: https://github.com/sebastianbergmann/php-code-coverage/compare/10.1.3...10.1.4
 [10.1.3]: https://github.com/sebastianbergmann/php-code-coverage/compare/10.1.2...10.1.3
 [10.1.2]: https://github.com/sebastianbergmann/php-code-coverage/compare/10.1.1...10.1.2
diff --git a/src/CodeCoverage.php b/src/CodeCoverage.php
index 43541bcea..f22b5f76c 100644
--- a/src/CodeCoverage.php
+++ b/src/CodeCoverage.php
@@ -106,6 +106,14 @@ public function clear(): void
         $this->cachedReport = null;
     }
 
+    /**
+     * @internal
+     */
+    public function clearCache(): void
+    {
+        $this->cachedReport = null;
+    }
+
     /**
      * Returns the filter object used.
      */
diff --git a/src/Report/PHP.php b/src/Report/PHP.php
index 2058fb39a..1f8186d04 100644
--- a/src/Report/PHP.php
+++ b/src/Report/PHP.php
@@ -21,6 +21,8 @@ final class PHP
 {
     public function process(CodeCoverage $coverage, ?string $target = null): string
     {
+        $coverage->clearCache();
+
         $buffer = "<?php
 return \unserialize(<<<'END_OF_COVERAGE_SERIALIZATION'" . PHP_EOL . serialize($coverage) . PHP_EOL . 'END_OF_COVERAGE_SERIALIZATION' . PHP_EOL . ');';
 
diff --git a/tests/tests/Report/PhpTest.php b/tests/tests/Report/PhpTest.php
index 657278bcd..75c11b4ba 100644
--- a/tests/tests/Report/PhpTest.php
+++ b/tests/tests/Report/PhpTest.php
@@ -9,6 +9,7 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report;
 
+use ReflectionProperty;
 use SebastianBergmann\CodeCoverage\TestCase;
 
 final class PhpTest extends TestCase
@@ -43,4 +44,22 @@ public function testPHPSerialisationProducesValidCodeWhenOutputIncludesSingleQuo
 
         $this->assertEquals($coverage, $unserialized);
     }
+
+    public function testCacheDataNeverGetSaved(): void
+    {
+        $coverage = $this->getLineCoverageForBankAccount();
+
+        // Warm up cache
+        $coverage->getReport();
+
+        $refProperty = new ReflectionProperty($coverage, 'cachedReport');
+        $refProperty->setAccessible(true);
+
+        $this->assertNotNull($refProperty->getValue($coverage));
+
+        /* @noinspection UnusedFunctionResultInspection */
+        (new PHP)->process($coverage, self::$TEST_TMP_PATH . '/serialized.php');
+
+        $this->assertNull($refProperty->getValue($coverage));
+    }
 }