diff --git a/src/Bootstrappers/BootSubscribers.php b/src/Bootstrappers/BootSubscribers.php
index f605d9be..5fa720ac 100644
--- a/src/Bootstrappers/BootSubscribers.php
+++ b/src/Bootstrappers/BootSubscribers.php
@@ -25,6 +25,7 @@ final readonly class BootSubscribers implements Bootstrapper
         Subscribers\EnsureIgnorableTestCasesAreIgnored::class,
         Subscribers\EnsureKernelDumpIsFlushed::class,
         Subscribers\EnsureTeamCityEnabled::class,
+        Subscribers\EnsureTiaIsRunningPestTestsOnly::class,
         Subscribers\EnsureTiaCoverageIsRecorded::class,
         Subscribers\EnsureTiaCoverageIsFlushed::class,
         Subscribers\EnsureTiaResultsAreCollected::class,
diff --git a/src/Exceptions/TiaRequiresPestTests.php b/src/Exceptions/TiaRequiresPestTests.php
new file mode 100644
index 00000000..603fcd05
--- /dev/null
+++ b/src/Exceptions/TiaRequiresPestTests.php
@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Exceptions;
+
+use NunoMaduro\Collision\Contracts\RenderlessEditor;
+use NunoMaduro\Collision\Contracts\RenderlessTrace;
+use Pest\Contracts\Panicable;
+use RuntimeException;
+use Symfony\Component\Console\Exception\ExceptionInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+/**
+ * @internal
+ */
+final class TiaRequiresPestTests extends RuntimeException implements ExceptionInterface, Panicable, RenderlessEditor, RenderlessTrace
+{
+    public function __construct(private readonly string $className, private readonly string $file)
+    {
+        parent::__construct(sprintf(
+            'Tia mode requires Pest tests, but encountered PHPUnit class [%s] in [%s].',
+            $className,
+            $file,
+        ));
+    }
+
+    public function render(OutputInterface $output): void
+    {
+        $output->writeln([
+            '',
+            '  <fg=white;options=bold;bg=red> ERROR </> Tia mode requires Pest tests.',
+            '',
+            sprintf('  Encountered PHPUnit class <fg=yellow>%s</>', $this->className),
+            sprintf('  in <fg=gray>%s</>.', $this->file),
+            '',
+            '  Convert it to a Pest test, or run without Tia.',
+            '',
+        ]);
+    }
+
+    public function exitCode(): int
+    {
+        return 1;
+    }
+}
diff --git a/src/Plugins/Tia.php b/src/Plugins/Tia.php
index 50c67593..4250c795 100644
--- a/src/Plugins/Tia.php
+++ b/src/Plugins/Tia.php
@@ -787,18 +787,18 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
         }
 
         $affectedFromChanges = $changed === [] ? [] : $graph->affected($changed);
-        $failedFromCache = [];
+        $rerunFromCache = [];
 
         if ($this->filteredMode) {
-            $failedFromCache = $graph->failedOrErroredTestFiles($this->branch);
+            $rerunFromCache = $graph->testFilesToRerun($this->branch);
         }
 
         $affected = array_values(array_unique([
             ...$affectedFromChanges,
-            ...$failedFromCache,
+            ...$rerunFromCache,
         ]));
 
-        $this->reportAffectedSummary($changed, $affectedFromChanges, $failedFromCache, $affected);
+        $this->reportAffectedSummary($changed, $affectedFromChanges, $rerunFromCache, $affected);
 
         $affectedSet = array_fill_keys($affected, true);
         $canRefreshReplayEdges = $affected !== [] && $coverageAvailable;
@@ -852,10 +852,10 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
     /**
      * @param  array<int, string>  $changedFiles
      * @param  array<int, string>  $affectedFromChanges
-     * @param  array<int, string>  $failedFromCache
+     * @param  array<int, string>  $rerunFromCache
      * @param  array<int, string>  $affected
      */
-    private function reportAffectedSummary(array $changedFiles, array $affectedFromChanges, array $failedFromCache, array $affected): void
+    private function reportAffectedSummary(array $changedFiles, array $affectedFromChanges, array $rerunFromCache, array $affected): void
     {
         $this->output->writeln('');
 
@@ -865,12 +865,12 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
             return;
         }
 
-        $newFailures = $failedFromCache === []
+        $newReruns = $rerunFromCache === []
             ? 0
-            : count(array_diff($failedFromCache, $affectedFromChanges));
+            : count(array_diff($rerunFromCache, $affectedFromChanges));
 
         $reasons = [];
-        $singleReason = (int) ($affectedFromChanges !== []) + (int) ($newFailures > 0) === 1;
+        $singleReason = (int) ($affectedFromChanges !== []) + (int) ($newReruns > 0) === 1;
 
         if ($affectedFromChanges !== []) {
             $reasons[] = $singleReason
@@ -887,17 +887,17 @@ final class Tia implements AddsOutput, HandlesArguments, Terminable
                 );
         }
 
-        if ($newFailures > 0) {
+        if ($newReruns > 0) {
             $reasons[] = $singleReason
                 ? sprintf(
-                    'from %d previous failure%s',
-                    $newFailures,
-                    $newFailures === 1 ? '' : 's',
+                    'from %d previously unsuccessful test%s',
+                    $newReruns,
+                    $newReruns === 1 ? '' : 's',
                 )
                 : sprintf(
-                    '%d from previous failure%s',
-                    $newFailures,
-                    $newFailures === 1 ? '' : 's',
+                    '%d from previously unsuccessful test%s',
+                    $newReruns,
+                    $newReruns === 1 ? '' : 's',
                 );
         }
 
diff --git a/src/Plugins/Tia/Graph.php b/src/Plugins/Tia/Graph.php
index 0010b8d9..c42b2fc6 100644
--- a/src/Plugins/Tia/Graph.php
+++ b/src/Plugins/Tia/Graph.php
@@ -516,13 +516,13 @@ final class Graph
     /**
      * @return array<int, string>
      */
-    public function failedOrErroredTestFiles(string $branch, string $fallbackBranch = 'main'): array
+    public function testFilesToRerun(string $branch, string $fallbackBranch = 'main'): array
     {
         $baseline = $this->baselineFor($branch, $fallbackBranch);
         $files = [];
 
         foreach ($baseline['results'] as $result) {
-            if ($result['status'] !== 7 && $result['status'] !== 8) {
+            if (! self::shouldRerun($result['status'])) {
                 continue;
             }
 
@@ -544,12 +544,12 @@ final class Graph
         return array_keys($files);
     }
 
-    public function hasUnlocatedFailuresOrErrors(string $branch, string $fallbackBranch = 'main'): bool
+    public function hasUnlocatedTestsToRerun(string $branch, string $fallbackBranch = 'main'): bool
     {
         $baseline = $this->baselineFor($branch, $fallbackBranch);
 
         foreach ($baseline['results'] as $result) {
-            if ($result['status'] !== 7 && $result['status'] !== 8) {
+            if (! self::shouldRerun($result['status'])) {
                 continue;
             }
 
@@ -563,6 +563,16 @@ final class Graph
         return false;
     }
 
+    private static function shouldRerun(int $status): bool
+    {
+        $testStatus = TestStatus::from($status);
+
+        return $testStatus->isFailure()
+            || $testStatus->isError()
+            || $testStatus->isIncomplete()
+            || $testStatus->isRisky();
+    }
+
     /**
      * @param  array<string, string>  $tree  project-relative path → content hash
      */
diff --git a/src/Plugins/Tia/Recorder.php b/src/Plugins/Tia/Recorder.php
index 57f66a6d..dfd319a7 100644
--- a/src/Plugins/Tia/Recorder.php
+++ b/src/Plugins/Tia/Recorder.php
@@ -119,8 +119,8 @@ final class Recorder
             $this->perTestUsesDatabase[$file] = true;
         }
 
-        $this->linkAncestorFiles($className);
-        $this->linkImportedFiles($file);
+        // $this->linkAncestorFiles($className);
+        // $this->linkImportedFiles($file);
 
         if ($this->driver === 'pcov') {
             \pcov\clear();
@@ -175,7 +175,7 @@ final class Recorder
             $this->perTestFiles[$this->currentTestFile][$sourceFile] = true;
         }
 
-        $this->linkSourceDependencies($coveredFiles);
+        // $this->linkSourceDependencies($coveredFiles);
 
         $this->currentTestFile = null;
         $this->includedFilesAtTestStart = [];
diff --git a/src/Plugins/Tia/ResultCollector.php b/src/Plugins/Tia/ResultCollector.php
index 09c6148a..1b84c8c8 100644
--- a/src/Plugins/Tia/ResultCollector.php
+++ b/src/Plugins/Tia/ResultCollector.php
@@ -4,6 +4,8 @@ declare(strict_types=1);
 
 namespace Pest\Plugins\Tia;
 
+use PHPUnit\Framework\TestStatus\TestStatus;
+
 /**
  * @internal
  */
@@ -33,7 +35,7 @@ final class ResultCollector
             return;
         }
 
-        $this->record(0, '');
+        $this->record(TestStatus::success());
     }
 
     public function testFailed(string $message): void
@@ -42,7 +44,7 @@ final class ResultCollector
             return;
         }
 
-        $this->record(7, $message);
+        $this->record(TestStatus::failure($message));
     }
 
     public function testErrored(string $message): void
@@ -51,7 +53,7 @@ final class ResultCollector
             return;
         }
 
-        $this->record(8, $message);
+        $this->record(TestStatus::error($message));
     }
 
     public function testSkipped(string $message): void
@@ -60,7 +62,7 @@ final class ResultCollector
             return;
         }
 
-        $this->record(1, $message);
+        $this->record(TestStatus::skipped($message));
     }
 
     public function testIncomplete(string $message): void
@@ -69,7 +71,7 @@ final class ResultCollector
             return;
         }
 
-        $this->record(2, $message);
+        $this->record(TestStatus::incomplete($message));
     }
 
     public function testRisky(string $message): void
@@ -78,7 +80,7 @@ final class ResultCollector
             return;
         }
 
-        $this->record(5, $message);
+        $this->record(TestStatus::risky($message));
     }
 
     /**
@@ -121,7 +123,7 @@ final class ResultCollector
         $this->startTime = null;
     }
 
-    private function record(int $status, string $message): void
+    private function record(TestStatus $status): void
     {
         if ($this->currentTestId === null) {
             return;
@@ -134,8 +136,8 @@ final class ResultCollector
         $existing = $this->results[$this->currentTestId] ?? null;
 
         $this->results[$this->currentTestId] = [
-            'status' => $status,
-            'message' => $message,
+            'status' => $status->asInt(),
+            'message' => $status->message(),
             'time' => $time,
             'assertions' => $existing['assertions'] ?? 0,
         ];
diff --git a/src/Subscribers/EnsureTiaIsRunningPestTestsOnly.php b/src/Subscribers/EnsureTiaIsRunningPestTestsOnly.php
new file mode 100644
index 00000000..591881e6
--- /dev/null
+++ b/src/Subscribers/EnsureTiaIsRunningPestTestsOnly.php
@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Subscribers;
+
+use Pest\Concerns\Testable;
+use Pest\Exceptions\TiaRequiresPestTests;
+use Pest\Panic;
+use Pest\Plugins\Tia\Recorder;
+use PHPUnit\Event\Code\TestMethod;
+use PHPUnit\Event\Test\Prepared;
+use PHPUnit\Event\Test\PreparedSubscriber;
+use ReflectionClass;
+
+/**
+ * @internal
+ */
+final readonly class EnsureTiaIsRunningPestTestsOnly implements PreparedSubscriber
+{
+    public function __construct(private Recorder $recorder) {}
+
+    public function notify(Prepared $event): void
+    {
+        if (! $this->recorder->isActive()) {
+            return;
+        }
+
+        $test = $event->test();
+
+        if (! $test instanceof TestMethod) {
+            return;
+        }
+
+        $className = $test->className();
+
+        if (! class_exists($className, false)) {
+            return;
+        }
+
+        if ($this->usesTestableTrait($className)) {
+            return;
+        }
+
+        Panic::with(new TiaRequiresPestTests($className, $test->file()));
+    }
+
+    private function usesTestableTrait(string $className): bool
+    {
+        $reflection = new ReflectionClass($className);
+
+        do {
+            foreach ($reflection->getTraitNames() as $trait) {
+                if ($trait === Testable::class) {
+                    return true;
+                }
+            }
+
+            $reflection = $reflection->getParentClass();
+        } while ($reflection !== false);
+
+        return false;
+    }
+}