diff --git a/wp-admin/includes/image.php b/wp-admin/includes/image.php
index 0f03e2ca42..573f107605 100644
--- a/wp-admin/includes/image.php
+++ b/wp-admin/includes/image.php
@@ -556,6 +556,11 @@ function file_is_valid_image( $path ) {
 function file_is_displayable_image( $path ) {
 	$displayable_image_types = array( IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG, IMAGETYPE_BMP );
 
+	// IMAGETYPE_ICO is only defined in PHP 5.3+.
+	if ( defined( 'IMAGETYPE_ICO' ) ) {
+		$displayable_image_types[] = IMAGETYPE_ICO;
+	}
+
 	$info = @getimagesize( $path );
 	if ( empty( $info ) ) {
 		$result = false;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index a918f6b97d..e87ab047d8 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-42779';
+$wp_version = '5.0-alpha-42780';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.