diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 6b15c7c49c..8cb08c2891 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -458,17 +458,17 @@ function xmlrpc_removepostdata( $content ) {
 function wp_extract_urls( $content ) {
 	preg_match_all(
 		"#("
-			. "(?: ([\w-]+:)?//? )"
+			. "(?:([\w-]+:)?//?)"
 			. "[^\s()<>]+"
 			. "[.]"
 			. "(?:"
-				. "\([\w\d]+\) |"
+				. "\([\w\d]+\)|"
 				. "(?:"
-					. "[^`!()\[\]{};:'\".,<>?«»“”‘’\s] |"
-					. "(?: [:]\d+ )?/?"
+					. "[^`!()\[\]{};:'\".,<>?«»“”‘’\s]|"
+					. "(?:[:]\d+)?/?"
 				. ")+"
 			. ")"
-		. ")#x",
+		. ")#",
 		$content,
 		$post_links
 	);