diff --git a/streamjs/streamjs-tests.ts b/streamjs/streamjs-tests.ts
index ba989f447..f911c8f52 100644
--- a/streamjs/streamjs-tests.ts
+++ b/streamjs/streamjs-tests.ts
@@ -1,4 +1,4 @@
-// <reference file="streamjs.d.ts" />
+/// <reference path="streamjs.d.ts" />
 
 var numStream: Stream<number>;
 numStream = Stream.of(1, 2, 3);
@@ -12,11 +12,11 @@ Stream.generate(() => 1);
 
 numStream = Stream.iterate(1, (n) => n * 2);
 
-var comparator = (s1, s2) => 0;
+var comparator = (s1: string, s2: string) => 0;
 
 numStream = numStream.filter(n => n % 2 == 0);
 var strStream = numStream
-					.dropWhile((n) => n % 2 == 0)
+					.dropWhile((n: number) => n % 2 == 0)
 					.map(n => "number " + n)
 					.dropWhile(/^$/)
 					.limit(100)
@@ -77,7 +77,7 @@ class MyList {
 
 var elems: any[];
 
-var myStream = Stream.from([new MyList, new MyList]);
+var myStream: Stream<MyList> = Stream.from([new MyList, new MyList]);
 elems = myStream
 	.flatMap(list => list.elems)
 	.toArray();
@@ -102,7 +102,7 @@ groupingResult = myStream.groupingBy(lst => lst.name);
 groupingResult = myStream.groupBy("name");
 groupingResult = myStream.groupingBy("name");
 
-var mappingResult = myStream.toMap(lst => lst.name, (e1, e2) => e2);
+var mappingResult = myStream.toMap((lst) => lst.name, (e1: MyList, e2: MyList) => e2);
 var aMappingResult: MyList = mappingResult["a"];
 
 mappingResult = myStream.toMap("a");
diff --git a/streamjs/streamjs.d.ts b/streamjs/streamjs.d.ts
index e36dcca23..59d8019f3 100644
--- a/streamjs/streamjs.d.ts
+++ b/streamjs/streamjs.d.ts
@@ -40,7 +40,7 @@ declare class Stream<T> {
 	groupBy(path: string): Stream.GroupingResult<T>;
 	groupingBy(mapper: Stream.Function<T, string>): Stream.GroupingResult<T>;
 	groupingBy(path: string): Stream.GroupingResult<T>;
-	indexBy(keyMapper: Stream.Function<T, string>, mergeFunction?: Stream.Accumulator<T>): T[];
+	indexBy(keyMapper: Stream.Function<T, string>, mergeFunction?: Stream.Accumulator<T>): Stream.Map<T>;
 	map <U> (mapper: Stream.Function<T, U>): Stream<U>;
 	max(): Stream.Optional<T>;
 	max(comparator: Stream.Comparator<T>): Stream.Optional<T>;
@@ -80,7 +80,7 @@ declare class Stream<T> {
 	sort(path: string): Stream<T>;
 	shuffle(): Stream<T>;
 	skip(n: number): Stream<T>;
-	slice(begin, end): Stream<T>;
+	slice(begin: number, end: number): Stream<T>;
 	sum(): number;
 	sum(path: string): number;
 	takeWhile(predicate: Stream.Predicate<T>): Stream<T>;
@@ -88,12 +88,17 @@ declare class Stream<T> {
 	takeWhile(sample: Stream.Sample): Stream<T>;
 	toArray(): T[];
 	toList(): T[];
-	toMap(keyMapper: Stream.Function<T, string>, mergeFunction?: Stream.Accumulator<T>): T[];
-	toMap(path: string, mergeFunction?: Stream.Accumulator<T>): T[];
+	toMap(keyMapper: Stream.Function<T, string>, mergeFunction?: Stream.Accumulator<T>): Stream.Map<T>;
+	toMap(path: string, mergeFunction?: Stream.Accumulator<T>): Stream.Map<T>;
 }
 
 declare module Stream {
 
+	export interface Map<T> {
+		[index: string]: T
+	}
+	
+
 	export interface Sample {
 		[index: string]: any
 	}