diff --git a/includes/gallery/SlideshowImageGallery.php b/includes/gallery/SlideshowImageGallery.php
index 3f0c9329d09..f29c565fc99 100644
--- a/includes/gallery/SlideshowImageGallery.php
+++ b/includes/gallery/SlideshowImageGallery.php
@@ -34,4 +34,8 @@ class SlideshowImageGallery extends TraditionalImageGallery {
 	protected function getModules() {
 		return [ 'mediawiki.page.gallery.slideshow' ];
 	}
+
+	public function setAdditionalOptions( $params ) {
+		$this->mAttribs['data-showthumbnails'] = isset( $params['showthumbnails'] );
+	}
 }
diff --git a/resources/src/mediawiki/page/gallery-slideshow.js b/resources/src/mediawiki/page/gallery-slideshow.js
index 094c4df3603..e651c9cc967 100644
--- a/resources/src/mediawiki/page/gallery-slideshow.js
+++ b/resources/src/mediawiki/page/gallery-slideshow.js
@@ -26,7 +26,7 @@
 		// Initialize
 		this.drawCarousel();
 		this.setSizeRequirement();
-		this.toggleThumbnails( false );
+		this.toggleThumbnails( !!this.$gallery.attr( 'data-showthumbnails' ) );
 		this.showCurrentImage();
 
 		// Events