diff --git a/source-map/index.d.ts b/source-map/index.d.ts
index dfddb63e27..8b8f800c85 100644
--- a/source-map/index.d.ts
+++ b/source-map/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for source-map v0.1.38
+// Type definitions for source-map v0.5.6
 // Project: https://github.com/mozilla/source-map
 // Definitions by: Morten Houston Ludvigsen <https://github.com/MortenHoustonLudvigsen>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
@@ -58,7 +58,7 @@ declare namespace SourceMap {
         public static GENERATED_ORDER: number;
         public static ORIGINAL_ORDER: number;
 
-        constructor(rawSourceMap: RawSourceMap);
+        constructor(rawSourceMap: RawSourceMap | string);
 
         public computeColumnSpans(): void;
 
@@ -115,9 +115,9 @@ declare namespace SourceMap {
             relativePath?: string
         ): SourceNode;
 
-        public add(chunk: any): SourceNode;
+        public add(chunk: (string | SourceNode)[] | SourceNode | string): SourceNode;
 
-        public prepend(chunk: any): SourceNode;
+        public prepend(chunk: (string | SourceNode)[] | SourceNode | string): SourceNode;
 
         public setSourceContent(sourceFile: string, sourceContent: string): void;
 
diff --git a/source-map/source-map-tests.ts b/source-map/source-map-tests.ts
index 23722d8179..4e584d2338 100644
--- a/source-map/source-map-tests.ts
+++ b/source-map/source-map-tests.ts
@@ -14,6 +14,15 @@ function testSourceMapConsumer() {
             file: 'sdf'
         });
 
+        scm = new SourceMap.SourceMapConsumer(JSON.stringify({
+            version: 3,
+            sources: ['foo', 'bar'],
+            names: ['foo', 'bar'],
+            sourcesContent: ['foo'],
+            mappings: 'foo',
+            file: 'sdf'
+        }));
+
         // create with partial RawSourceMap
         scm = new SourceMap.SourceMapConsumer({
             version: 3,
@@ -129,10 +138,14 @@ function testSourceNode() {
 
     function testAdd(node: SourceMap.SourceNode) {
         node.add('foo');
+        node.add(new SourceMap.SourceNode());
+        node.add([new SourceMap.SourceNode(), 'bar']);
     }
 
     function testPrepend(node: SourceMap.SourceNode) {
         node.prepend('foo');
+        node.prepend(new SourceMap.SourceNode());
+        node.prepend([new SourceMap.SourceNode(), 'bar']);
     }
 
     function testSetSourceContent(node: SourceMap.SourceNode) {