diff --git a/includes/utils.php b/includes/utils.php
index 70ba7dbcc..764a4b1a4 100644
--- a/includes/utils.php
+++ b/includes/utils.php
@@ -204,6 +204,10 @@ function is_site_indexable( $blog_id = null ) {
 
 	$site = get_site( $blog_id );
 
+	if ( empty( $site ) ) {
+		return false;
+	}
+
 	$is_indexable = get_site_meta( $site['blog_id'], 'ep_indexable', true );
 
 	return 'no' !== $is_indexable && ! $site['deleted'] && ! $site['archived'] && ! $site['spam'];
@@ -303,6 +307,10 @@ function get_host() {
 function get_site( $site_id ) {
 	$site = \get_site( $site_id );
 
+	if ( ! $site instanceof \WP_Site ) {
+		return [];
+	}
+
 	return [
 		'blog_id'  => $site->blog_id,
 		'domain'   => $site->domain,
diff --git a/tests/php/TestUtils.php b/tests/php/TestUtils.php
index f2f0c8777..8df958db3 100644
--- a/tests/php/TestUtils.php
+++ b/tests/php/TestUtils.php
@@ -100,6 +100,29 @@ public function testIsSiteIndexableDisabled() {
 		$this->assertFalse( ElasticPress\Utils\is_site_indexable() );
 	}
 
+	/**
+	 * Check that get_site returns an empty array for a non-existent site ID.
+	 *
+	 * @since 5.3.4
+	 * @group utils
+	 * @group skip-on-single-site
+	 */
+	public function testGetSiteReturnsEmptyArrayForNonexistentSite() {
+		$result = ElasticPress\Utils\get_site( 999999 );
+		$this->assertSame( [], $result );
+	}
+
+	/**
+	 * Check that is_site_indexable returns false for a non-existent site ID.
+	 *
+	 * @since 5.3.4
+	 * @group utils
+	 * @group skip-on-single-site
+	 */
+	public function testIsSiteIndexableReturnsFalseForNonexistentSite() {
+		$this->assertFalse( ElasticPress\Utils\is_site_indexable( 999999 ) );
+	}
+
 	/**
 	 * Tests the sanitize_credentials utils function.
 	 *