diff --git a/src/wp-includes/class-wp-customize-manager.php b/src/wp-includes/class-wp-customize-manager.php
index 33977544d4..79f2b3eab3 100644
--- a/src/wp-includes/class-wp-customize-manager.php
+++ b/src/wp-includes/class-wp-customize-manager.php
@@ -4273,7 +4273,7 @@ final class WP_Customize_Manager {
 		<script type="text/html" id="tmpl-customize-changeset-locked-notification">
 			<li class="notice notice-{{ data.type || 'info' }} {{ data.containerClasses || '' }}" data-code="{{ data.code }}" data-type="{{ data.type }}">
 				<div class="notification-message customize-changeset-locked-message">
-					<img class="customize-changeset-locked-avatar" src="{{ data.lockUser.avatar }}" alt="{{ data.lockUser.name }}">
+					<img class="customize-changeset-locked-avatar" src="{{ data.lockUser.avatar }}" alt="{{ data.lockUser.name }}" />
 					<p class="currently-editing">
 						<# if ( data.message ) { #>
 							{{{ data.message }}}
diff --git a/src/wp-includes/customize/class-wp-customize-header-image-control.php b/src/wp-includes/customize/class-wp-customize-header-image-control.php
index 739a10bb6d..82c1714261 100644
--- a/src/wp-includes/customize/class-wp-customize-header-image-control.php
+++ b/src/wp-includes/customize/class-wp-customize-header-image-control.php
@@ -133,7 +133,7 @@ class WP_Customize_Header_Image_Control extends WP_Customize_Image_Control {
 				data-customize-image-value="{{{data.header.url}}}"
 				data-customize-header-image-data="{{JSON.stringify(data.header)}}">
 				<span class="screen-reader-text"><?php _e( 'Set image' ); ?></span>
-				<img src="{{{data.header.thumbnail_url}}}" alt="{{{data.header.alt_text || data.header.description}}}">
+				<img src="{{{data.header.thumbnail_url}}}" alt="{{{data.header.alt_text || data.header.description}}}" />
 			</button>
 
 			<# if ( data.type === 'uploaded' ) { #>