diff -up ./src/SpdxLicenses.php.rpm ./src/SpdxLicenses.php
--- ./src/SpdxLicenses.php.rpm	2021-11-18 13:15:53.000000000 +0100
+++ ./src/SpdxLicenses.php	2021-11-18 13:22:10.402686746 +0100
@@ -213,7 +213,7 @@ class SpdxLicenses
      */
     public static function getResourcesDir()
     {
-        return dirname(__DIR__) . '/res';
+        return (getenv('BUILDROOT_SPDX')?:'') . '/usr/share/php-composer-spdx-licenses';
     }
 
     /**
diff -up ./tests/SpdxLicensesTest.php.rpm ./tests/SpdxLicensesTest.php
--- ./tests/SpdxLicensesTest.php.rpm	2021-11-18 13:15:53.000000000 +0100
+++ ./tests/SpdxLicensesTest.php	2021-11-18 13:21:44.972772614 +0100
@@ -75,12 +75,6 @@ class SpdxLicensesTest extends TestCase
             is_dir($dir),
             'Expected resources directory to exist.'
         );
-
-        $this->assertEquals(
-            realpath($dir),
-            realpath(__DIR__ . '/../res'),
-            'Expected resources directory to be "res" (relative to project root).'
-        );
     }
 
     /**