diff --git a/http/Provision/Config/Apache/SubdirVhost.php b/http/Provision/Config/Apache/SubdirVhost.php
index bb7fe71b865d9db9c29ded5569044350ddba64d7..0420a1fde674cf9f355f35ab845e9a09464fa017 100644
--- a/http/Provision/Config/Apache/SubdirVhost.php
+++ b/http/Provision/Config/Apache/SubdirVhost.php
@@ -32,8 +32,15 @@ class Provision_Config_Apache_SubdirVhost extends Provision_Config_Http {
     foreach (d()->aliases as $alias) {
       if (strpos($alias, '/')) {
         $this->current_alias = $alias;
-        drush_log("Subdirectory alias `$alias` found. Creating vhost configuration file.", 'notice');
-        parent::write();
+        if (d($this->uri())) {
+          drush_log(dt('virtual host %vhost already exist for alias %alias, skipping', array('%vhost' => $this->uri(), '%alias' => $alias)), 'warning');
+          // XXX: we need to verify that vhost here, or at least
+          // generate its configuration file.
+        }
+        else {
+          drush_log("Subdirectory alias `$alias` found. Creating vhost configuration file.", 'notice');
+          parent::write();
+        }
       }
     }
   }
diff --git a/subdirs/subdirs.drush.inc b/subdirs/subdirs.drush.inc
index 02d11784b7702f272d61f1aa17359b86098cd112..ee321ab0ee24764eea1e00a71085944087664760 100644
--- a/subdirs/subdirs.drush.inc
+++ b/subdirs/subdirs.drush.inc
@@ -117,3 +117,18 @@ function _subdirs_remove_symlinks() {
     }
   }
 }
+
+/**
+ * Inject our includes into existing virtual host
+ *
+ * Implementation of hook_provision_apache_vhost_config().
+ *
+ * This is the case where example.com exists for the alias example.com/foo.
+ */
+function subdirs_provision_apache_vhost_config($uri, $data) {
+  $subdirs_path = $data['http_subdird_path'] . '/' . $uri . '/*.conf'; // wild guess
+  if (glob($subdirs_path)) {
+    return "# subdirectory sites for this virtual host
+Include $subdirs_path";
+  }
+}