diff --git a/src/DrupalFinderComposerRuntime.php b/src/DrupalFinderComposerRuntime.php
index 238561e..baf927b 100644
--- a/src/DrupalFinderComposerRuntime.php
+++ b/src/DrupalFinderComposerRuntime.php
@@ -17,8 +17,12 @@ class DrupalFinderComposerRuntime
      */
     public function getDrupalRoot(): ?string
     {
-        $core = InstalledVersions::getInstallPath('drupal/core');
-        return $core ? realpath(dirname($core)) : null;
+        try {
+            $core = InstalledVersions::getInstallPath('drupal/core');
+            return $core ? realpath(dirname($core)) : null;
+        } catch (\OutOfBoundsException) {
+            return null;
+        }
     }
 
     /**