diff --git a/externals/JsShrink/jsShrink.php b/externals/JsShrink/jsShrink.php
index 36f1c39335..239e6d7978 100644
--- a/externals/JsShrink/jsShrink.php
+++ b/externals/JsShrink/jsShrink.php
@@ -13,7 +13,11 @@ function jsShrink($input) {
 		(?:
 			(^|[-+\([{}=,:;!%^&*|?~]|/(?![/*])|return|throw) # context before regexp
 			(?:\s|//[^\n]*+\n|/\*(?:[^*]|\*(?!/))*+\*/)* # optional space
-			(/(?![/*])(?:\\\\[^\n]|[^[\n/\\\\]|\[(?:\\\\[^\n]|[^]])++)+/) # regexp
+			(/(?![/*])(?:
+				\\\\[^\n]
+				|[^[\n/\\\\]++
+				|\[(?:\\\\[^\n]|[^]])++
+			)+/) # regexp
 			|(^
 				|\'(?:\\\\.|[^\n\'\\\\])*\'
 				|"(?:\\\\.|[^\n"\\\\])*"