diff --git a/wp-includes/class-wp-query.php b/wp-includes/class-wp-query.php
index a6c248a7bf..6d2cdfa391 100644
--- a/wp-includes/class-wp-query.php
+++ b/wp-includes/class-wp-query.php
@@ -4000,6 +4000,10 @@ class WP_Query {
 			$content = str_replace( "\n<!--nextpage-->", '<!--nextpage-->', $content );
 			$content = str_replace( "<!--nextpage-->\n", '<!--nextpage-->', $content );
 
+			// Remove the nextpage block delimiters, to avoid invalid block structures in the split content.
+			$content = str_replace( '<!-- wp:nextpage -->', '', $content );
+			$content = str_replace( '<!-- /wp:nextpage -->', '', $content );
+
 			// Ignore nextpage at the beginning of the content.
 			if ( 0 === strpos( $content, '<!--nextpage-->' ) )
 				$content = substr( $content, 15 );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index cb61776f6c..6eec6742da 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-beta5-43939';
+$wp_version = '5.0-beta5-43940';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.