diff --git a/types/crossfilter/crossfilter-tests.ts b/types/crossfilter/crossfilter-tests.ts
index e96d83a7e2..78dfdab696 100644
--- a/types/crossfilter/crossfilter-tests.ts
+++ b/types/crossfilter/crossfilter-tests.ts
@@ -62,9 +62,7 @@ var paymentGroupsByTotal = paymentsByTotal.group(total => Math.floor(total / 100
 
 paymentGroupsByTotal.size();
 
-// bug of TS 0.9.5 https://typescript.codeplex.com/discussions/471751
-//paymentGroupsByTotal.reduce((p, v) => p + 1, (p, v) => p - 1, () => 0);
-paymentGroupsByTotal.reduce<number>((p, v) => p + 1, (p, v) => p - 1, () => 0);
+paymentGroupsByTotal.reduce((p, v) => p + 1, (p, v) => p - 1, () => 0);
 
 paymentGroupsByTotal.reduceCount();
 
@@ -115,6 +113,12 @@ topTypes[0].value; // the count of payments of that type (e.g., 8)
 
 var types = paymentCountByType.all();
 
+// $ExpectError
+types.sort();
+
+types[0].key;
+types[0].value;
+
 paymentsByTotal.dispose();
 
 crossfilter.bisect([], null, 0, 0);
diff --git a/types/crossfilter/index.d.ts b/types/crossfilter/index.d.ts
index bae8a06565..918d9771a9 100644
--- a/types/crossfilter/index.d.ts
+++ b/types/crossfilter/index.d.ts
@@ -1,6 +1,6 @@
 // Type definitions for CrossFilter
 // Project: https://github.com/square/crossfilter
-// Definitions by: Schmulik Raskin <https://github.com/schmuli>, Izaak Baker <https://github.com/iebaker>, Einar Norðfjörð <https://github.com/nordfjord>
+// Definitions by: Schmulik Raskin <https://github.com/schmuli>, Izaak Baker <https://github.com/iebaker>, Einar Norðfjörð <https://github.com/nordfjord>, Tijmen Wildervanck <https://github.com/TijmenW>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 declare namespace CrossFilter {
@@ -73,7 +73,7 @@ declare namespace CrossFilter {
 
     export interface Group<T, TKey, TValue> {
         top(k: number): Grouping<TKey, TValue>[];
-        all(): Grouping<TKey, TValue>[];
+        all(): ReadonlyArray<Grouping<TKey, TValue>>;
         reduce<TGroup>(add: (p: TGroup, v: T) => TGroup, remove: (p: TGroup, v: T) => TGroup, initial: () => TGroup): Group<T, TKey, TGroup>;
         reduceCount(): Group<T, TKey, number>;
         reduceSum<TGroup>(value: (data: T) => TGroup): Group<T, TKey, TGroup>;