diff --git a/inc/functions.php b/inc/functions.php
index f0e5f66..608aad0 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -115,7 +115,12 @@ function accelerate_scripts_styles_method() {
 //	wp_enqueue_style( 'accelerate-fontawesome', get_template_directory_uri() . '/fontawesome/css/font-awesome.css', array(), '4.7.0' );
 
 	wp_enqueue_script( 'html5shiv', ACCELERATE_JS_URL . '/html5shiv.js', array(), '3.7.3', false );
-	wp_script_add_data( 'html5shiv', 'conditional', 'lte IE 8' );
+
+	// The 'conditional' data key is deprecated since WP 6.9.0 and has no effect there;
+	// only set it on older versions to keep html5shiv restricted to IE8 and below.
+	if ( version_compare( $GLOBALS['wp_version'], '6.9', '<' ) ) {
+		wp_script_add_data( 'html5shiv', 'conditional', 'lte IE 8' );
+	}
 }
 
 function accelerate_block_editor_styles() {