diff --git a/lib/injectSubsetDefinitions.js b/lib/injectSubsetDefinitions.js
index ee531a96..4ddd0c75 100644
--- a/lib/injectSubsetDefinitions.js
+++ b/lib/injectSubsetDefinitions.js
@@ -5,30 +5,28 @@ function injectSubsetDefinitions(cssValue, webfontNameMap, replaceOriginal) {
   const subsetFontNames = new Set(
     Object.values(webfontNameMap).map(name => name.toLowerCase())
   );
-  const tokens = postcssValuesParser(cssValue).tokens;
-  let resultStr = '';
+  const rootNode = postcssValuesParser.parse(cssValue);
   let isPreceededByWords = false;
-  for (let i = 0; i < tokens.length; i += 1) {
-    const token = tokens[i];
+  for (const [i, node] of rootNode.nodes.entries()) {
     let possibleFontFamily;
     let lastFontFamilyTokenIndex = i;
-    if (token[0] === 'string') {
-      possibleFontFamily = unquote(token[1]);
-    } else if (token[0] === 'word') {
+    if (node.type === 'quoted') {
+      possibleFontFamily = unquote(node.value);
+    } else if (node.type === 'word') {
       if (!isPreceededByWords) {
         const wordSequence = [];
-        for (let j = i; j < tokens.length; j += 1) {
-          if (tokens[j][0] === 'word') {
-            wordSequence.push(tokens[j][1]);
+        for (let j = i; j < rootNode.nodes.length; j += 1) {
+          if (rootNode.nodes[j].type === 'word') {
+            wordSequence.push(rootNode.nodes[j].value);
             lastFontFamilyTokenIndex = j;
-          } else if (tokens[j][0] !== 'space') {
+          } else {
             break;
           }
         }
         possibleFontFamily = wordSequence.join(' ');
       }
       isPreceededByWords = true;
-    } else if (token[0] !== 'space') {
+    } else {
       isPreceededByWords = false;
     }
     if (possibleFontFamily) {
@@ -37,10 +35,14 @@ function injectSubsetDefinitions(cssValue, webfontNameMap, replaceOriginal) {
         // Bail out, a subset font is already listed
         return cssValue;
       } else if (webfontNameMap[possibleFontFamilyLowerCase]) {
-        resultStr += `'${webfontNameMap[possibleFontFamilyLowerCase].replace(
-          /'/g,
-          "\\'"
-        )}'`;
+        rootNode.insertBefore(
+          node,
+          `'${webfontNameMap[possibleFontFamilyLowerCase].replace(
+            /'/g,
+            "\\'"
+          )}', `
+        );
+        return rootNode.toString();
         if (replaceOriginal) {
           tokens.splice(i, lastFontFamilyTokenIndex - i + 1);
           i -= 1;
@@ -50,9 +52,8 @@ function injectSubsetDefinitions(cssValue, webfontNameMap, replaceOriginal) {
         }
       }
     }
-    resultStr += token[1];
   }
-  return resultStr;
+  return cssValue;
 }
 
 module.exports = injectSubsetDefinitions;
diff --git a/lib/injectSubsetDefinitions.js.orig b/lib/injectSubsetDefinitions.js.orig
new file mode 100644
index 00000000..ee531a96
--- /dev/null
+++ b/lib/injectSubsetDefinitions.js.orig
@@ -0,0 +1,58 @@
+const postcssValuesParser = require('postcss-values-parser');
+const unquote = require('./unquote');
+
+function injectSubsetDefinitions(cssValue, webfontNameMap, replaceOriginal) {
+  const subsetFontNames = new Set(
+    Object.values(webfontNameMap).map(name => name.toLowerCase())
+  );
+  const tokens = postcssValuesParser(cssValue).tokens;
+  let resultStr = '';
+  let isPreceededByWords = false;
+  for (let i = 0; i < tokens.length; i += 1) {
+    const token = tokens[i];
+    let possibleFontFamily;
+    let lastFontFamilyTokenIndex = i;
+    if (token[0] === 'string') {
+      possibleFontFamily = unquote(token[1]);
+    } else if (token[0] === 'word') {
+      if (!isPreceededByWords) {
+        const wordSequence = [];
+        for (let j = i; j < tokens.length; j += 1) {
+          if (tokens[j][0] === 'word') {
+            wordSequence.push(tokens[j][1]);
+            lastFontFamilyTokenIndex = j;
+          } else if (tokens[j][0] !== 'space') {
+            break;
+          }
+        }
+        possibleFontFamily = wordSequence.join(' ');
+      }
+      isPreceededByWords = true;
+    } else if (token[0] !== 'space') {
+      isPreceededByWords = false;
+    }
+    if (possibleFontFamily) {
+      const possibleFontFamilyLowerCase = possibleFontFamily.toLowerCase();
+      if (subsetFontNames.has(possibleFontFamilyLowerCase)) {
+        // Bail out, a subset font is already listed
+        return cssValue;
+      } else if (webfontNameMap[possibleFontFamilyLowerCase]) {
+        resultStr += `'${webfontNameMap[possibleFontFamilyLowerCase].replace(
+          /'/g,
+          "\\'"
+        )}'`;
+        if (replaceOriginal) {
+          tokens.splice(i, lastFontFamilyTokenIndex - i + 1);
+          i -= 1;
+          continue;
+        } else {
+          resultStr += ', ';
+        }
+      }
+    }
+    resultStr += token[1];
+  }
+  return resultStr;
+}
+
+module.exports = injectSubsetDefinitions;
diff --git a/lib/injectSubsetDefinitions.js.rej b/lib/injectSubsetDefinitions.js.rej
new file mode 100644
index 00000000..1bd73495
--- /dev/null
+++ b/lib/injectSubsetDefinitions.js.rej
@@ -0,0 +1,66 @@
+--- lib/util/fonts/injectSubsetDefinitions.js
++++ lib/util/fonts/injectSubsetDefinitions.js
+@@ -5,28 +5,26 @@ function injectSubsetDefinitions(cssValue, webfontNameMap) {
+   const subsetFontNames = new Set(
+     Object.values(webfontNameMap).map(name => name.toLowerCase())
+   );
+-  const tokens = postcssValuesParser(cssValue).tokens;
+-  let resultStr = '';
++  const rootNode = postcssValuesParser.parse(cssValue);
+   let isPreceededByWords = false;
+-  for (let i = 0; i < tokens.length; i += 1) {
+-    const token = tokens[i];
++  for (const [i, node] of rootNode.nodes.entries()) {
+     let possibleFontFamily;
+-    if (token[0] === 'string') {
+-      possibleFontFamily = unquote(token[1]);
+-    } else if (token[0] === 'word') {
++    if (node.type === 'quoted') {
++      possibleFontFamily = unquote(node.value);
++    } else if (node.type === 'word') {
+       if (!isPreceededByWords) {
+         const wordSequence = [];
+-        for (let j = i; j < tokens.length; j += 1) {
+-          if (tokens[j][0] === 'word') {
+-            wordSequence.push(tokens[j][1]);
+-          } else if (tokens[j][0] !== 'space') {
++        for (let j = i; j < rootNode.nodes.length; j += 1) {
++          if (rootNode.nodes[j].type === 'word') {
++            wordSequence.push(rootNode.nodes[j].value);
++          } else {
+             break;
+           }
+         }
+         possibleFontFamily = wordSequence.join(' ');
+       }
+       isPreceededByWords = true;
+-    } else if (token[0] !== 'space') {
++    } else {
+       isPreceededByWords = false;
+     }
+     if (possibleFontFamily) {
+@@ -35,15 +33,18 @@ function injectSubsetDefinitions(cssValue, webfontNameMap) {
+       if (subsetFontNames.has(possibleFontFamilyLowerCase)) {
+         return cssValue;
+       } else if (webfontNameMap[possibleFontFamilyLowerCase]) {
+-        resultStr += `'${webfontNameMap[possibleFontFamilyLowerCase].replace(
+-          /'/g,
+-          "\\'"
+-        )}', `;
++        rootNode.insertBefore(
++          node,
++          `'${webfontNameMap[possibleFontFamilyLowerCase].replace(
++            /'/g,
++            "\\'"
++          )}', `
++        );
++        return rootNode.toString();
+       }
+     }
+-    resultStr += token[1];
+   }
+-  return resultStr;
++  return cssValue;
+ }
+ 
+ module.exports = injectSubsetDefinitions;
diff --git a/package.json b/package.json
index 287a86ce..0be538a2 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,7 @@
     "font-tracer": "^1.1.0",
     "fontkit": "^1.8.0",
     "lodash.groupby": "^4.6.0",
-    "postcss-values-parser": "^2.0.1",
+    "postcss-values-parser": "^3.0.5",
     "pretty-bytes": "^5.1.0",
     "urltools": "^0.4.1",
     "yargs": "^12.0.2"
diff --git a/test/injectSubsetDefinitions.js b/test/injectSubsetDefinitions.js
index 4559690d..8773f971 100644
--- a/test/injectSubsetDefinitions.js
+++ b/test/injectSubsetDefinitions.js
@@ -42,7 +42,7 @@ describe('injectSubsetDefinitions', function() {
     expect(
       injectSubsetDefinitions('times   new   roman', webfontNameMap),
       'to equal',
-      "'times new roman__subset', times   new   roman"
+      "'times new roman__subset', times new roman"
     );
   });