diff --git a/acorn/src/parseutil.js b/acorn/src/parseutil.js
index bce71b54e..7ef24a6da 100644
--- a/acorn/src/parseutil.js
+++ b/acorn/src/parseutil.js
@@ -6,7 +6,7 @@ const pp = Parser.prototype
 
 // ## Parser utilities
 
-const literal = /^(?:'((?:\\.|[^'])*?)'|"((?:\\.|[^"])*?)")/
+const literal = /^(?:'((?:\\.|[^'\\])*?)'|"((?:\\.|[^"\\])*?)")/
 pp.strictDirective = function(start) {
   for (;;) {
     // Try to find string literal.