diff --git a/lib/rules_text/smartquotes.js b/lib/rules_text/smartquotes.js
index 02bcbd0..3482412 100644
--- a/lib/rules_text/smartquotes.js
+++ b/lib/rules_text/smartquotes.js
@@ -16,19 +16,19 @@ function isLetter(str, pos) {
 }
 
 
-function addQuote(obj, tokenId, posId, str) {
-  if (typeof obj[tokenId] === 'undefined') { obj[tokenId] = {}; }
-  obj[tokenId][posId] = str;
+function replaceAt(str, index, ch) {
+  return str.substr(0, index) + ch + str.substr(index + 1);
 }
 
+var stack = [];
 
 module.exports = function smartquotes(typographer, state) {
   /*eslint max-depth:0*/
-  var i, token, text, t, pos, max, thisLevel, lastSpace, nextSpace, item, canOpen, canClose, j, isSingle, fn, chars,
+  var i, token, text, t, pos, max, thisLevel, lastSpace, nextSpace, item, canOpen, canClose, j, isSingle, chars,
       options = typographer.options,
-      replace = {},
-      tokens = state.tokens,
-      stack = [];
+      tokens = state.tokens;
+
+  stack.length = 0;
 
   for (i = 0; i < tokens.length; i++) {
     token = tokens[i];
@@ -46,20 +46,22 @@ module.exports = function smartquotes(typographer, state) {
     pos = 0;
     max = text.length;
 
+    /*eslint no-labels:0,block-scoped-var:0*/
+    OUTER:
     while (pos < max) {
       QUOTE_RE.lastIndex = pos;
       t = QUOTE_RE.exec(text);
       if (!t) { break; }
 
       lastSpace = !isLetter(text, t.index - 1);
-      pos = t.index + t[0].length;
-      isSingle = t[0] === "'";
+      pos = t.index + 1;
+      isSingle = (t[0] === "'");
       nextSpace = !isLetter(text, pos);
 
       if (!nextSpace && !lastSpace) {
-        // middle word
+        // middle of word
         if (isSingle) {
-          addQuote(replace, i, t.index, APOSTROPHE);
+          token.content = replaceAt(token.content, t.index, APOSTROPHE);
         }
         continue;
       }
@@ -76,12 +78,11 @@ module.exports = function smartquotes(typographer, state) {
             item = stack[j];
             chars = isSingle ? options.singleQuotes : options.doubleQuotes;
             if (chars) {
-              addQuote(replace, item.token, item.start, chars[0]);
-              addQuote(replace, i, t.index, chars[1]);
+              tokens[item.token].content = replaceAt(tokens[item.token].content, item.pos, chars[0]);
+              token.content = replaceAt(token.content, t.index, chars[1]);
             }
             stack.length = j;
-            canOpen = false; // should be "continue OUTER;", but eslint refuses labels :(
-            break;
+            continue OUTER;
           }
         }
       }
@@ -89,25 +90,13 @@ module.exports = function smartquotes(typographer, state) {
       if (canOpen) {
         stack.push({
           token: i,
-          start: t.index,
-          end: pos,
+          pos: t.index,
           single: isSingle,
           level: thisLevel
         });
       } else if (canClose && isSingle) {
-        addQuote(replace, i, t.index, APOSTROPHE);
+        token.content = replaceAt(token.content, t.index, APOSTROPHE);
       }
     }
   }
-
-  fn = function(str, pos) {
-    if (typeof replace[i][pos] === 'undefined') { return str; }
-    return replace[i][pos];
-  };
-
-  for (i = 0; i < tokens.length; i++) {
-    if (typeof replace[i] === 'undefined') { continue; }
-    QUOTE_RE.lastIndex = 0;
-    tokens[i].content = tokens[i].content.replace(QUOTE_RE, fn);
-  }
 };