diff --git a/src/wp-signup.php b/src/wp-signup.php
index 314421713e..824ba1a7f9 100644
--- a/src/wp-signup.php
+++ b/src/wp-signup.php
@@ -40,6 +40,13 @@ if ( !is_main_site() ) {
 // Fix for page title
 $wp_query->is_404 = false;
 
+/**
+ * Fires before the Site Signup page is loaded.
+ *
+ * @since 4.4.0
+ */
+do_action( 'before_signup_header' );
+
 /**
  * Prints styles for front-end Multisite signup pages
  *