diff --git a/acorn/src/parseutil.js b/acorn/src/parseutil.js
index 730642c37..9e0be0a8b 100644
--- a/acorn/src/parseutil.js
+++ b/acorn/src/parseutil.js
@@ -6,7 +6,7 @@ const pp = Parser.prototype
 
 // ## Parser utilities
 
-const literal = /^(?:'((?:\\.|[^'\\])*?)'|"((?:\\.|[^"\\])*?)")/s
+const literal = /^(?:'((?:\\[^]|[^'\\])*?)'|"((?:\\[^]|[^"\\])*?)")/
 pp.strictDirective = function(start) {
   if (this.options.ecmaVersion < 5) return false
   for (;;) {