diff --git a/ChangeLog-9.6.md b/ChangeLog-9.6.md
index 9793f193f43..bd6292ae33a 100644
--- a/ChangeLog-9.6.md
+++ b/ChangeLog-9.6.md
@@ -4,4 +4,8 @@ All notable changes of the PHPUnit 9.6 release series are documented in this fil
 
 ## [9.6.0] - 2023-02-03
 
+### Changed
+
+* [#5132](https://github.com/sebastianbergmann/phpunit/issues/5132): Deprecate `Test` suffix for abstract test case classes
+
 [9.6.0]: https://github.com/sebastianbergmann/phpunit/compare/9.5...9.6
diff --git a/src/Framework/TestSuite.php b/src/Framework/TestSuite.php
index ce738533f05..a51538b18d0 100644
--- a/src/Framework/TestSuite.php
+++ b/src/Framework/TestSuite.php
@@ -456,6 +456,15 @@ public function addTestFile(string $filename): void
                 continue;
             }
 
+            if ($class->isAbstract() && $class->isSubclassOf(TestCase::class)) {
+                $this->addWarning(
+                    sprintf(
+                        'Abstract test case classes with "Test" suffix are deprecated (%s)',
+                        $class->getName()
+                    )
+                );
+            }
+
             if (!$class->isAbstract()) {
                 if ($class->hasMethod(BaseTestRunner::SUITE_METHODNAME)) {
                     try {
diff --git a/tests/end-to-end/generic/abstract-test-class/directory-with-concrete-test-class-and-abstract-test-class-with-test-suffix.phpt b/tests/end-to-end/generic/abstract-test-class/directory-with-concrete-test-class-and-abstract-test-class-with-test-suffix.phpt
index 35bf84383fb..a97d201bc93 100644
--- a/tests/end-to-end/generic/abstract-test-class/directory-with-concrete-test-class-and-abstract-test-class-with-test-suffix.phpt
+++ b/tests/end-to-end/generic/abstract-test-class/directory-with-concrete-test-class-and-abstract-test-class-with-test-suffix.phpt
@@ -11,6 +11,8 @@ PHPUnit\TextUI\Command::main();
 --EXPECTF--
 PHPUnit %s by Sebastian Bergmann and contributors.
 
+Warning:       Abstract test case classes with "Test" suffix are deprecated (PHPUnit\TestFixture\AbstractTest)
+
 .                                                                   1 / 1 (100%)
 
 Time: %s, Memory: %s
diff --git a/tests/end-to-end/generic/test-suffix-multiple.phpt b/tests/end-to-end/generic/test-suffix-multiple.phpt
index 5302accc6cd..3451cca0498 100644
--- a/tests/end-to-end/generic/test-suffix-multiple.phpt
+++ b/tests/end-to-end/generic/test-suffix-multiple.phpt
@@ -19,6 +19,7 @@ Warning:       Test case class not matching filename is deprecated
 Warning:       Test case class not matching filename is deprecated
                in %sConcreteTest.my.php
                Class name was 'ConcreteWithMyCustomExtensionTest', expected 'ConcreteTest'
+Warning:       Abstract test case classes with "Test" suffix are deprecated (PHPUnit\TestFixture\AbstractTest)
 
 .....                                                               5 / 5 (100%)