diff --git a/app/Services/PhotoPreview.php b/app/Services/PhotoPreview.php
index d10424a..57663c4 100644
--- a/app/Services/PhotoPreview.php
+++ b/app/Services/PhotoPreview.php
@@ -261,19 +261,16 @@ class PhotoPreview
     private function resolveBinary(string $name): ?string
     {
         $candidates = match ($name) {
-            'magick' => [base_path('bin/magick'), 'magick', '/opt/homebrew/bin/magick', '/usr/local/bin/magick', '/usr/bin/magick'],
-            'convert' => ['convert', '/usr/bin/convert'],
-            'heif-convert' => [base_path('bin/heif-convert'), 'heif-convert', '/usr/bin/heif-convert', '/usr/local/bin/heif-convert'],
-            'heif-dec' => [base_path('bin/heif-dec'), 'heif-dec', '/usr/bin/heif-dec', '/usr/local/bin/heif-dec'],
+            'magick' => [base_path('bin/magick'), '/opt/homebrew/bin/magick', '/usr/local/bin/magick', '/usr/bin/magick', 'magick'],
+            'convert' => [base_path('bin/convert'), '/usr/bin/convert', 'convert'],
+            'heif-convert' => [base_path('bin/heif-convert'), '/usr/bin/heif-convert', '/usr/local/bin/heif-convert', 'heif-convert'],
+            'heif-dec' => [base_path('bin/heif-dec'), '/usr/bin/heif-dec', '/usr/local/bin/heif-dec', 'heif-dec'],
             default => [$name],
         };
+        $outside = null;
         $bare = null;
         foreach ($candidates as $bin) {
             if (! str_contains($bin, DIRECTORY_SEPARATOR)) {
-                $found = $this->which($bin);
-                if ($found !== null) {
-                    return $found;
-                }
                 $bare ??= $bin;
 
                 continue;
@@ -281,26 +278,13 @@ class PhotoPreview
             if ($this->isSafeExecutable($bin)) {
                 return $bin;
             }
-        }
-
-        // exec() is often allowed when is_executable() is not; let Process try PATH.
-        return $bare;
-    }
-
-    private function which(string $name): ?string
-    {
-        $path = getenv('PATH');
-        if (! is_string($path) || $path === '') {
-            return null;
-        }
-        foreach (explode(PATH_SEPARATOR, $path) as $dir) {
-            $candidate = rtrim($dir, DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR.$name;
-            if ($this->isSafeExecutable($candidate)) {
-                return $candidate;
+            // Panel open_basedir blocks PHP from stat() /usr/bin, but proc_open can still run it.
+            if (! $this->isPathInsideOpenBasedir($bin)) {
+                $outside ??= $bin;
             }
         }
 
-        return null;
+        return $outside ?? $bare;
     }
 
     private function isSafeExecutable(string $path): bool
@@ -318,14 +302,30 @@ class PhotoPreview
         if ($basedir === '') {
             return true;
         }
-        $real = realpath($path);
-        $check = $real !== false ? $real : $path;
+        $roots = [];
         foreach (explode(PATH_SEPARATOR, $basedir) as $root) {
             $root = rtrim($root, DIRECTORY_SEPARATOR);
-            if ($root === '') {
-                continue;
+            if ($root !== '') {
+                $roots[] = $root;
             }
-            if ($check === $root || str_starts_with($check, $root.DIRECTORY_SEPARATOR)) {
+        }
+        if ($this->pathPrefixedByRoot($path, $roots)) {
+            $real = @realpath($path);
+            $check = is_string($real) && $real !== '' ? $real : $path;
+
+            return $this->pathPrefixedByRoot($check, $roots);
+        }
+
+        return false;
+    }
+
+    /**
+     * @param  list<string>  $roots
+     */
+    private function pathPrefixedByRoot(string $path, array $roots): bool
+    {
+        foreach ($roots as $root) {
+            if ($path === $root || str_starts_with($path, $root.DIRECTORY_SEPARATOR)) {
                 return true;
             }
         }
diff --git a/tests/Unit/PhotoPreviewTest.php b/tests/Unit/PhotoPreviewTest.php
index 1af13f2..0edd8fc 100644
--- a/tests/Unit/PhotoPreviewTest.php
+++ b/tests/Unit/PhotoPreviewTest.php
@@ -10,6 +10,18 @@ use Tests\TestCase;
 
 class PhotoPreviewTest extends TestCase
 {
+    #[Test]
+    public function basedir_probe_does_not_realpath_system_bins(): void
+    {
+        $preview = new PhotoPreview;
+        $ref = new \ReflectionMethod(PhotoPreview::class, 'isPathInsideOpenBasedir');
+        $this->assertFalse($ref->invoke($preview, '/usr/bin/heif-convert')
+            && (string) ini_get('open_basedir') !== ''
+            && ! str_contains((string) ini_get('open_basedir'), '/usr/bin'));
+        $resolved = (new \ReflectionMethod(PhotoPreview::class, 'resolveBinary'))->invoke($preview, 'heif-convert');
+        $this->assertNotNull($resolved);
+    }
+
     #[Test]
     public function detects_heic_ftyp_header(): void
     {