diff --git a/src/url-state-machine.js b/src/url-state-machine.js
index ee6dcd7df..05f9746a5 100644
--- a/src/url-state-machine.js
+++ b/src/url-state-machine.js
@@ -43,6 +43,37 @@ function isASCIIHex(c) {
   return isASCIIDigit(c) || (c >= 0x41 && c <= 0x46) || (c >= 0x61 && c <= 0x66);
 }
 
+const urlCodePoints = [
+  p("!"), p("$"), p("'"), p("("), p(")"), p("*"),
+  p("+"), p(","), p("-"), p("."), p("/"), p(":"),
+  p(";"), p("="), p("?"), p("@"), p("_"), p("~")
+];
+function isURLCodePoint(c) {
+  return (
+    isASCIIAlphanumeric(c) ||
+    urlCodePoints.indexOf(c) !== -1 ||
+    (c >= 0xA0 && c <= 0xD7FF) ||
+    (c >= 0xE000 && c <= 0xFDCF) ||
+    (c >= 0xFDF0 && c <= 0xFFFD) ||
+    (c >= 0x10000 && c <= 0x1FFFD) ||
+    (c >= 0x20000 && c <= 0x2FFFD) ||
+    (c >= 0x30000 && c <= 0x3FFFD) ||
+    (c >= 0x40000 && c <= 0x4FFFD) ||
+    (c >= 0x50000 && c <= 0x5FFFD) ||
+    (c >= 0x60000 && c <= 0x6FFFD) ||
+    (c >= 0x70000 && c <= 0x7FFFD) ||
+    (c >= 0x80000 && c <= 0x8FFFD) ||
+    (c >= 0x90000 && c <= 0x9FFFD) ||
+    (c >= 0xA0000 && c <= 0xAFFFD) ||
+    (c >= 0xB0000 && c <= 0xBFFFD) ||
+    (c >= 0xC0000 && c <= 0xCFFFD) ||
+    (c >= 0xD0000 && c <= 0xDFFFD) ||
+    (c >= 0xE0000 && c <= 0xEFFFD) ||
+    (c >= 0xF0000 && c <= 0xFFFFD) ||
+    (c >= 0x100000 && c <= 0x10FFFD)
+  );
+}
+
 function isSingleDot(buffer) {
   return buffer === "." || buffer.toLowerCase() === "%2e";
 }
@@ -946,7 +977,9 @@ URLStateMachine.prototype["parse path"] = function parsePath(c) {
       this.state = "fragment";
     }
   } else {
-    // TODO: If c is not a URL code point and not "%", parse error.
+    if (!isURLCodePoint(c) && c !== p("%")) {
+      this.parseError = true;
+    }
 
     if (c === p("%") &&
       (!isASCIIHex(this.input[this.pointer + 1]) ||
@@ -975,8 +1008,7 @@ URLStateMachine.prototype["parse cannot-be-a-base-URL path"] = function parseCan
     this.url.fragment = "";
     this.state = "fragment";
   } else {
-    // TODO: Add: not a URL code point
-    if (!isNaN(c) && c !== p("%")) {
+    if (!isNaN(c) && !isURLCodePoint(c) && c !== p("%")) {
       this.parseError = true;
     }
 
@@ -1016,7 +1048,10 @@ URLStateMachine.prototype["parse query"] = function parseQuery(c, cStr) {
       this.state = "fragment";
     }
   } else {
-    // TODO: If c is not a URL code point and not "%", parse error.
+    if (!isURLCodePoint(c) && c !== p("%")) {
+      this.parseError = true;
+    }
+
     if (c === p("%") &&
       (!isASCIIHex(this.input[this.pointer + 1]) ||
         !isASCIIHex(this.input[this.pointer + 2]))) {
@@ -1034,7 +1069,10 @@ URLStateMachine.prototype["parse fragment"] = function parseFragment(c, cStr) {
   } else if (c === 0x0) {
     this.parseError = true;
   } else {
-    // TODO: If c is not a URL code point and not "%", parse error.
+    if (!isURLCodePoint(c) && c !== p("%")) {
+      this.parseError = true;
+    }
+
     if (c === p("%") &&
       (!isASCIIHex(this.input[this.pointer + 1]) ||
         !isASCIIHex(this.input[this.pointer + 2]))) {