diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
index 26fe0a3674..a84ffce694 100644
--- a/src/wp-includes/general-template.php
+++ b/src/wp-includes/general-template.php
@@ -1081,7 +1081,7 @@ function get_custom_logo( $blog_id = 0 ) {
 	} elseif ( is_customize_preview() ) {
 		// If no logo is set but we're in the Customizer, leave a placeholder (needed for the live preview).
 		$html = sprintf(
-			'<a href="%1$s" class="custom-logo-link" style="display:none;"><img class="custom-logo"/></a>',
+			'<a href="%1$s" class="custom-logo-link" style="display:none;"><img class="custom-logo" alt="" /></a>',
 			esc_url( home_url( '/' ) )
 		);
 	}