diff --git a/src/wp-includes/js/customize-base.js b/src/wp-includes/js/customize-base.js
index a1528de4ff..3fdb92423f 100644
--- a/src/wp-includes/js/customize-base.js
+++ b/src/wp-includes/js/customize-base.js
@@ -655,7 +655,7 @@ window.wp = window.wp || {};
 				var urlParser = document.createElement( 'a' );
 				urlParser.href = to;
 				// Port stripping needed by IE since it adds to host but not to event.origin.
-				return urlParser.protocol + '//' + urlParser.host.replace( /:80$/, '' );
+				return urlParser.protocol + '//' + urlParser.host.replace( /:(80|443)$/, '' );
 			});
 
 			// first add with no value
diff --git a/src/wp-includes/js/customize-preview.js b/src/wp-includes/js/customize-preview.js
index 7b8804d3ed..adb9f03847 100644
--- a/src/wp-includes/js/customize-preview.js
+++ b/src/wp-includes/js/customize-preview.js
@@ -286,11 +286,11 @@
 			return false;
 		}
 
-		elementHost = element.host.replace( /:80$/, '' );
+		elementHost = element.host.replace( /:(80|443)$/, '' );
 		parsedAllowedUrl = document.createElement( 'a' );
 		matchesAllowedUrl = ! _.isUndefined( _.find( api.settings.url.allowed, function( allowedUrl ) {
 			parsedAllowedUrl.href = allowedUrl;
-			return parsedAllowedUrl.protocol === element.protocol && parsedAllowedUrl.host.replace( /:80$/, '' ) === elementHost && 0 === element.pathname.indexOf( parsedAllowedUrl.pathname.replace( /\/$/, '' ) );
+			return parsedAllowedUrl.protocol === element.protocol && parsedAllowedUrl.host.replace( /:(80|443)$/, '' ) === elementHost && 0 === element.pathname.indexOf( parsedAllowedUrl.pathname.replace( /\/$/, '' ) );
 		} ) );
 		if ( ! matchesAllowedUrl ) {
 			return false;