diff --git a/lib/output.js b/lib/output.js
index 7f7e74df..1c0a6bb6 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -111,10 +111,9 @@ function OutputStream(options) {
     var OUTPUT = "";
 
     var to_utf8 = options.ascii_only ? function(str, identifier) {
-        return str.replace(/[\u0000-\u001f\u007f-\uffff]/g, function(ch) {
+        return str.replace(/[\u0080-\uffff]/g, function(ch) {
             var code = ch.charCodeAt(0).toString(16);
             if (code.length <= 2 && !identifier) {
-                while (code.length < 2) code = "0" + code;
                 return "\\x" + code;
             } else {
                 while (code.length < 4) code = "0" + code;
@@ -136,7 +135,7 @@ function OutputStream(options) {
 
     function make_string(str, quote) {
         var dq = 0, sq = 0;
-        str = str.replace(/[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff]/g,
+        str = str.replace(/[\\\0-\x1f\x22\x27\x7f\u2028\u2029\ufeff]/g,
           function(s, i) {
             switch (s) {
               case '"': ++dq; return '"';
@@ -153,6 +152,10 @@ function OutputStream(options) {
               case "\ufeff": return "\\ufeff";
               case "\0":
                   return /[0-9]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
+              default:
+                  var code = s.charCodeAt(0).toString(16);
+                  if (code.length < 2) code = "0" + code;
+                  return "\\x" + code;
             }
             return s;
         });
diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 3c7cc5cf..2933bec7 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -31,5 +31,5 @@ ascii_only_false: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\x008\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
 }
diff --git a/test/mocha/string-literal.js b/test/mocha/string-literal.js
index aca915b7..2d292a85 100644
--- a/test/mocha/string-literal.js
+++ b/test/mocha/string-literal.js
@@ -65,7 +65,7 @@ describe("String literals", function() {
             ['"\\008"', '"\\x008";'],
             ['"\\0008"', '"\\x008";'],
             ['"use strict" === "use strict";\n"\\76";', '"use strict"==="use strict";">";'],
-            ['"use\\\n strict";\n"\\07";', ';"use strict";"\07";']
+            ['"use\\\n strict";\n"\\07";', ';"use strict";"\\x07";']
         ];
 
         for (var test in tests) {