diff --git a/src/Handler.php b/src/Handler.php
index cfce435dbf84af241ad8c4d9de85f846bda68e22..06a6f2ac8bfeb4d616a0f7db981cda0f1aba50a2 100644
--- a/src/Handler.php
+++ b/src/Handler.php
@@ -70,6 +70,10 @@ class Handler {
     // Directory where the root project is being created.
     $projectRoot = getcwd();
     $full_name = $this->composer->getPackage()->getName();
+    if (strpos($full_name, '/') === FALSE) {
+      // We are too early, composer.json not configured yet.
+      return;
+    }
     [, $project_name] = explode('/', $full_name);
     $moduleRoot = $projectRoot . "/web/modules/custom/$project_name";