diff --git a/docs/performance.md b/docs/performance.md
index bb507ebb..829045d8 100644
--- a/docs/performance.md
+++ b/docs/performance.md
@@ -56,7 +56,7 @@ return require $file;               // happy path: no stat(), just cached opcode
 A missing compiled script is a build invariant violation (corrupt or incomplete build); PHP 8 makes a
 failed `require` a catchable `Error` that surfaces naturally. `CompiledInjector::getInstance()` keeps its
 `file_exists()` pre-check (it reports unbound interfaces as `Unbound`); its redundant
-`realpath($this->scriptDir)` — already canonicalised in the constructor — was removed.
+`realpath($this->scriptDir)` — already validated in the constructor — was removed.
 
 ## Benchmarking correctly
 
diff --git a/src/CompiledInjector.php b/src/CompiledInjector.php
index eace33ab..595a47bc 100644
--- a/src/CompiledInjector.php
+++ b/src/CompiledInjector.php
@@ -66,8 +66,13 @@ final class CompiledInjector implements ScriptInjectorInterface
     public function __construct(#[ScriptDir]
     string $scriptDir,)
     {
+        // realpath() cannot resolve stream URIs such as phar://; keep those as given
         $realPath = realpath($scriptDir);
-        if ($realPath === false || ! is_dir($realPath) || ! is_readable($realPath)) {
+        if ($realPath === false) {
+            $realPath = $scriptDir;
+        }
+
+        if (! is_dir($realPath) || ! is_readable($realPath)) {
             $message = sprintf('Script directory "%s" is not readable. See https://ray-di.github.io/Ray.Compiler/error/ScriptDirNotReadable', $scriptDir);
 
             throw new ScriptDirNotReadable($message);
@@ -112,7 +117,7 @@ public function getInstance($interface, $name = Name::ANY)
 
         /** @psalm-suppress  UnsupportedPropertyReferenceUsage */
         $singletons = &$this->singletons;
-        $scriptDir = $this->scriptDir; // already realpath()d in the constructor
+        $scriptDir = $this->scriptDir; // validated in the constructor
 
         // $scriptDir, $singletons, and $dependencyIndex can be used in the included file
         /** @var mixed $instance */
diff --git a/tests/CompiledInjectorTest.php b/tests/CompiledInjectorTest.php
index 896803af..1d8dd46b 100644
--- a/tests/CompiledInjectorTest.php
+++ b/tests/CompiledInjectorTest.php
@@ -10,11 +10,17 @@
 use Ray\Compiler\Exception\ScriptDirNotReadable;
 use Ray\Di\Exception\Unbound;
 
+use function escapeshellarg;
+use function exec;
+use function implode;
 use function mkdir;
 use function serialize;
 use function spl_object_hash;
+use function sprintf;
 use function unserialize;
 
+use const PHP_BINARY;
+
 /** @psalm-import-type ScriptDir from CompiledInjector */
 class CompiledInjectorTest extends TestCase
 {
@@ -111,4 +117,29 @@ public function testThrowsScriptDirNotReadableException(): void
         $this->expectExceptionMessage($scriptDir);
         new CompiledInjector($scriptDir);
     }
+
+    /**
+     * realpath() returns false for phar:// paths, but compiled scripts are
+     * relocatable (see ScriptDirRelocationTest) and phars can carry them.
+     */
+    public function testScriptDirInsidePhar(): void
+    {
+        $scriptDir = __DIR__ . '/tmp/' . __FUNCTION__;
+        @mkdir($scriptDir);
+        (new Compiler())->compile(new FakeModule(), $scriptDir);
+        $pharFile = $scriptDir . '.phar'; // outside $scriptDir so the build never globs its own output
+        // The test process runs with phar.readonly=1; build in a child that does not
+        exec(sprintf(
+            '%s -d phar.readonly=0 %s %s %s 2>&1',
+            escapeshellarg(PHP_BINARY),
+            escapeshellarg(__DIR__ . '/script/build_phar.php'),
+            escapeshellarg($scriptDir),
+            escapeshellarg($pharFile),
+        ), $output, $exitCode);
+        $this->assertSame(0, $exitCode, implode("\n", $output));
+
+        $injector = new CompiledInjector('phar://' . $pharFile . '/di');
+        $instance = $injector->getInstance(FakeCarInterface::class);
+        $this->assertInstanceOf(FakeCarInterface::class, $instance);
+    }
 }
diff --git a/tests/script/build_phar.php b/tests/script/build_phar.php
new file mode 100644
index 00000000..7f5ca5bc
--- /dev/null
+++ b/tests/script/build_phar.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * Build a phar whose /di directory holds the given compiled scripts.
+ *
+ * Run with -d phar.readonly=0; the test suite itself runs read-only.
+ *
+ * argv: [1] compiled script directory (flat), [2] phar file to create
+ */
+
+declare(strict_types=1);
+
+@unlink($argv[2]); // Phar appends to an existing archive; start clean
+$phar = new Phar($argv[2]);
+$phar->startBuffering();
+foreach (array_filter((array) glob($argv[1] . '/*')) as $file) {
+    $phar->addFile($file, 'di/' . basename($file));
+}
+
+$phar->stopBuffering();