diff --git a/modules/@angular/router/src/url_serializer.ts b/modules/@angular/router/src/url_serializer.ts
index b6502760e5..62ebad2405 100644
--- a/modules/@angular/router/src/url_serializer.ts
+++ b/modules/@angular/router/src/url_serializer.ts
@@ -1,5 +1,5 @@
 import {PRIMARY_OUTLET} from './shared';
-import {UrlPathWithParams, UrlSegment, UrlTree} from './url_tree';
+import {UrlPathWithParams, UrlSegment, UrlTree, mapChildrenIntoArray} from './url_tree';
 import {forEach} from './utils/collection';
 
 
@@ -54,38 +54,22 @@ function serializeSegment(segment: UrlSegment, root: boolean): string {
     } else {
       return `${primary}`;
     }
-  } else if (segment.children[PRIMARY_OUTLET] && !root) {
-    const children = [serializeSegment(segment.children[PRIMARY_OUTLET], false)];
-    forEach(segment.children, (v: UrlSegment, k: string) => {
-      if (k !== PRIMARY_OUTLET) {
-        children.push(`${k}:${serializeSegment(v, false)}`);
+
+  } else if (segment.hasChildren() && !root) {
+    const children = mapChildrenIntoArray(segment, (v: UrlSegment, k: string) => {
+      if (k === PRIMARY_OUTLET) {
+        return [serializeSegment(segment.children[PRIMARY_OUTLET], false)];
+      } else {
+        return [`${k}:${serializeSegment(v, false)}`];
       }
     });
     return `${serializePaths(segment)}/(${children.join('//')})`;
+
   } else {
     return serializePaths(segment);
   }
 }
 
-function serializeChildren(segment: UrlSegment) {
-  if (segment.children[PRIMARY_OUTLET]) {
-    const primary = serializePaths(segment.children[PRIMARY_OUTLET]);
-
-    const secondary: string[] = [];
-    forEach(segment.children, (v: UrlSegment, k: string) => {
-      if (k !== PRIMARY_OUTLET) {
-        secondary.push(`${k}:${serializePaths(v)}${serializeChildren(v)}`);
-      }
-    });
-    const secondaryStr = secondary.length > 0 ? `(${secondary.join('//')})` : '';
-    const primaryChildren = serializeChildren(segment.children[PRIMARY_OUTLET]);
-    const primaryChildrenStr: string = primaryChildren ? `/${primaryChildren}` : '';
-    return `${primary}${secondaryStr}${primaryChildrenStr}`;
-  } else {
-    return '';
-  }
-}
-
 export function serializePath(path: UrlPathWithParams): string {
   return `${path.path}${serializeParams(path.parameters)}`;
 }
diff --git a/modules/@angular/router/src/url_tree.ts b/modules/@angular/router/src/url_tree.ts
index 9cb4a7b711..9188a73943 100644
--- a/modules/@angular/router/src/url_tree.ts
+++ b/modules/@angular/router/src/url_tree.ts
@@ -74,6 +74,8 @@ export class UrlSegment {
     forEach(children, (v: any, k: any) => v.parent = this);
   }
 
+  hasChildren(): boolean { return Object.keys(this.children).length > 0; }
+
   toString(): string { return serializePaths(this); }
 }
 
diff --git a/modules/@angular/router/test/url_serializer.spec.ts b/modules/@angular/router/test/url_serializer.spec.ts
index 804212f471..dcf88e30fa 100644
--- a/modules/@angular/router/test/url_serializer.spec.ts
+++ b/modules/@angular/router/test/url_serializer.spec.ts
@@ -28,6 +28,33 @@ describe('url serializer', () => {
     expect(url.serialize(tree)).toEqual("/one/two(left:three//right:four)");
   });
 
+  it("should parse segments with empty paths", () => {
+    const tree = url.parse("/one/two/(;a=1//right:;b=2)");
+
+    const c = tree.root.children[PRIMARY_OUTLET];
+    expectSegment(tree.root.children[PRIMARY_OUTLET], "one/two", true);
+
+    expect(c.children[PRIMARY_OUTLET].pathsWithParams[0].path).toEqual('');
+    expect(c.children[PRIMARY_OUTLET].pathsWithParams[0].parameters).toEqual({a: '1'});
+
+    expect(c.children['right'].pathsWithParams[0].path).toEqual('');
+    expect(c.children['right'].pathsWithParams[0].parameters).toEqual({b: '2'});
+
+    expect(url.serialize(tree)).toEqual("/one/two/(;a=1//right:;b=2)");
+  });
+
+  it("should parse segments with empty paths (only aux)", () => {
+    const tree = url.parse("/one/two/(right:;b=2)");
+
+    const c = tree.root.children[PRIMARY_OUTLET];
+    expectSegment(tree.root.children[PRIMARY_OUTLET], "one/two", true);
+
+    expect(c.children['right'].pathsWithParams[0].path).toEqual('');
+    expect(c.children['right'].pathsWithParams[0].parameters).toEqual({b: '2'});
+
+    expect(url.serialize(tree)).toEqual("/one/two/(right:;b=2)");
+  });
+
   it("should parse scoped secondary segments", () => {
     const tree = url.parse("/one/(two//left:three)");