diff --git a/inc/template-tags.php b/inc/template-tags.php
index d1403d4..6a0330b 100644
--- a/inc/template-tags.php
+++ b/inc/template-tags.php
@@ -133,3 +133,36 @@ function _s_post_thumbnail() {
 	<?php endif; // End is_singular().
 }
 endif;
+
+if ( ! function_exists( '_s_post_thumbnail' ) ) :
+/**
+ * Displays an optional post thumbnail.
+ *
+ * Wraps the post thumbnail in an anchor element on index views, or a div
+ * element when on single views.
+ */
+function _s_post_thumbnail() {
+	if ( post_password_required() || is_attachment() || ! has_post_thumbnail() ) {
+		return;
+	}
+
+	if ( is_singular() ) :
+	?>
+
+	<div class="post-thumbnail">
+		<?php the_post_thumbnail(); ?>
+	</div><!-- .post-thumbnail -->
+
+	<?php else : ?>
+
+	<a class="post-thumbnail" href="<?php the_permalink(); ?>" aria-hidden="true">
+		<?php
+			the_post_thumbnail( 'post-thumbnail', array(
+				'alt' => the_title_attribute( 'echo=0' ),
+			) );
+		?>
+	</a>
+
+	<?php endif; // End is_singular().
+}
+endif;