diff --git a/lib/underscore.js b/lib/underscore.js
index e3b10642..091c376a 100644
--- a/lib/underscore.js
+++ b/lib/underscore.js
@@ -2,7 +2,7 @@
 
 declare module "underscore" {
   declare function find<T>(list: T[], predicate: (val: T)=>boolean): ?T;
-  declare function findWhere<T>(list: Array<T>, properties: {}): ?T;
+  declare function findWhere<T>(list: Array<T>, properties: {[key:string]: any}): ?T;
   declare function clone<T>(obj: T): T;
 
   declare function isEqual<S, T>(a: S, b: T): boolean;
diff --git a/src/main/pileup.js b/src/main/pileup.js
index c858089d..4aaf5b17 100644
--- a/src/main/pileup.js
+++ b/src/main/pileup.js
@@ -47,7 +47,7 @@ type PileupParams = {
 }
 
 function findReference(tracks: VisualizedTrack[]): ?VisualizedTrack {
-  return _.findWhere(tracks, t => t.track.isReference);
+  return _.find(tracks, t => !!t.track.isReference);
 }
 
 function create(elOrId: string|Element, params: PileupParams): Pileup {
diff --git a/src/main/types.js b/src/main/types.js
index 8eafb2c7..c613d51f 100644
--- a/src/main/types.js
+++ b/src/main/types.js
@@ -18,6 +18,7 @@ export type Track = {
   data: Object;  // This is a DataSource object
   name?: string;
   cssClass?: string;
+  isReference?: boolean
 }
 
 export type VisualizedTrack = {
diff --git a/src/test/components-test.js b/src/test/components-test.js
index 9edfeaab..e938bae8 100644
--- a/src/test/components-test.js
+++ b/src/test/components-test.js
@@ -9,6 +9,16 @@ var pileup = require('../main/pileup'),
     
 describe('pileup', function() {
   var tracks = [
+    {
+      viz: pileup.viz.scale(),
+      data: pileup.formats.empty(),
+      name: 'Scale'
+    },
+    {
+      viz: pileup.viz.location(),
+      data: pileup.formats.empty(),
+      name: 'Location'
+    },
     {
       viz: pileup.viz.genome(),
       isReference: true,
@@ -33,16 +43,6 @@ describe('pileup', function() {
       }),
       cssClass: 'c'
     },
-    {
-      viz: pileup.viz.scale(),
-      data: pileup.formats.empty(),
-      name: 'Scale'
-    },
-    {
-      viz: pileup.viz.location(),
-      data: pileup.formats.empty(),
-      name: 'Location'
-    },
     {
       viz: pileup.viz.pileup(),
       data: pileup.formats.bam({