diff --git a/wp-includes/post-functions.php b/wp-includes/post-functions.php
index 05663968de..1c410d7674 100644
--- a/wp-includes/post-functions.php
+++ b/wp-includes/post-functions.php
@@ -835,10 +835,11 @@ function get_post_type( $post = null ) {
 function get_post_type_object( $post_type ) {
 	global $wp_post_types;
 
-	if ( empty($wp_post_types[$post_type]) )
+	if ( ! is_scalar( $post_type ) || empty( $wp_post_types[ $post_type ] ) ) {
 		return null;
+	}
 
-	return $wp_post_types[$post_type];
+	return $wp_post_types[ $post_type ];
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index f188597f8b..e31d2011fe 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34099';
+$wp_version = '4.4-alpha-34100';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.