diff --git a/wp-admin/edit-form-advanced.php b/wp-admin/edit-form-advanced.php
index d92e8c4..5631d49 100644
--- a/wp-admin/edit-form-advanced.php
+++ b/wp-admin/edit-form-advanced.php
@@ -474,7 +474,7 @@ if ( post_type_supports($post_type, 'editor') ) {
 <?php wp_editor( $post->post_content, 'content', array(
 	'dfw' => true,
 	'tabfocus_elements' => 'insert-media-button,save-post',
-	'editor_height' => in_array( $post_format, array( 'status', 'aside' ) ) ? 120 : 360
+	'editor_height' => isset( $post_format ) && in_array( $post_format, array( 'status', 'aside' ) ) ? 120 : 360
 ) ); ?>
 <table id="post-status-info" cellspacing="0"><tbody><tr>
 	<td id="wp-word-count"><?php printf( __( 'Word count: %s' ), '<span class="word-count">0</span>' ); ?></td>