diff --git src/wp-content/themes/twentyseventeen/assets/js/customize-controls.js src/wp-content/themes/twentyseventeen/assets/js/customize-controls.js
index b8e7e8160c..e6f6037a4d 100644
--- src/wp-content/themes/twentyseventeen/assets/js/customize-controls.js
+++ src/wp-content/themes/twentyseventeen/assets/js/customize-controls.js
@@ -25,10 +25,12 @@
 		});
 
 		// Detect when the front page sections section is expanded (or closed) so we can adjust the preview accordingly.
-		wp.customize.section( 'theme_options' ).expanded.bind( function( isExpanding ) {
+		wp.customize.section( 'theme_options', function( section ) {
+			section.expanded.bind( function( isExpanding ) {
 
-			// Value of isExpanding will = true if you're entering the section, false if you're leaving it.
-			wp.customize.previewer.send( 'section-highlight', { expanded: isExpanding });
-		});
+				// Value of isExpanding will = true if you're entering the section, false if you're leaving it.
+				wp.customize.previewer.send( 'section-highlight', { expanded: isExpanding });
+			} );
+		} );
 	});
 })( jQuery );