diff --git a/types/istanbul-lib-source-maps/index.d.ts b/types/istanbul-lib-source-maps/index.d.ts
index 12569d62cd..45f7f3d05d 100644
--- a/types/istanbul-lib-source-maps/index.d.ts
+++ b/types/istanbul-lib-source-maps/index.d.ts
@@ -1,43 +1,43 @@
-// Type definitions for istanbul-lib-source-maps 1.2
+// Type definitions for istanbul-lib-source-maps 4.0
 // Project: https://istanbul.js.org, https://github.com/istanbuljs/istanbuljs
 // Definitions by: Jason Cheatham <https://github.com/jason0x43>
+//                 Sridhar Mallela <https://github.com/sridharmallela>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.4
 
 import { CoverageMap } from 'istanbul-lib-coverage';
 import { RawSourceMap } from 'source-map';
 
-export function createSourceMapStore(
-	options?: Partial<MapStoreOptions>
-): MapStore;
+export function createSourceMapStore(options?: Partial<MapStoreOptions>): MapStore;
 
 export interface MapStoreOptions {
-	verbose: boolean;
-	baseDir: string;
-	sourceStore: 'memory' | 'file';
-	tmpdir: string;
+    verbose: boolean;
+    baseDir: string;
+    sourceStore: 'memory' | 'file';
+    tmpdir: string;
 }
 
 export interface MapStore {
-	baseDir: string | null;
-	verbose: boolean;
-	sourceStore: SourceStore;
-	data: {
-		[filepath: string]: {
-			type: string;
-			data: any;
-		};
-	};
+    baseDir: string | null;
+    verbose: boolean;
+    sourceStore: SourceStore;
+    data: {
+        [filepath: string]: {
+            type: string;
+            data: any;
+        };
+    };
 
-	registerURL(transformedFilePath: string, sourceMapUrl: string): void;
-	registerMap(filename: string, sourceMap: RawSourceMap): void;
-	transformCoverage(
-		coverageMap: CoverageMap
-	): { map: CoverageMap; sourceFinder(path: string): string };
-	dispose(): void;
+    registerURL(transformedFilePath: string, sourceMapUrl: string): void;
+    registerMap(filename: string, sourceMap: RawSourceMap): void;
+    getSourceMapSync(filePath: string): any;
+    addInputSourceMapsSync(coverageData: any): void;
+    sourceFinder(filePath: string): string;
+    transformCoverage(coverageMap: CoverageMap): CoverageMap;
+    dispose(): void;
 }
 
 export class SourceStore {
-	getSource(filepath: string): string | null;
-	registerSource(filepath: string, sourceText: string): void;
+    getSource(filepath: string): string | null;
+    registerSource(filepath: string, sourceText: string): void;
 }
diff --git a/types/istanbul-lib-source-maps/istanbul-lib-source-maps-tests.ts b/types/istanbul-lib-source-maps/istanbul-lib-source-maps-tests.ts
index 844205df8d..68fdf24fa8 100644
--- a/types/istanbul-lib-source-maps/istanbul-lib-source-maps-tests.ts
+++ b/types/istanbul-lib-source-maps/istanbul-lib-source-maps-tests.ts
@@ -1,24 +1,24 @@
-import { createSourceMapStore } from 'istanbul-lib-source-maps';
 import { CoverageMap } from 'istanbul-lib-coverage';
 import { RawSourceMap } from 'source-map';
+import { createSourceMapStore } from 'istanbul-lib-source-maps';
 
 createSourceMapStore();
 createSourceMapStore({});
 const store = createSourceMapStore({
-	verbose: false,
-	baseDir: 'foo',
-	sourceStore: 'memory',
-	tmpdir: 'foo'
+    verbose: false,
+    baseDir: 'foo',
+    sourceStore: 'memory',
+    tmpdir: 'foo',
 });
 
 store.data['foo'].type.trim();
 
 const sourceMap: RawSourceMap = {
-	version: 1 as any as string, // Fixed by https://github.com/mozilla/source-map/pull/293 but the fix is not yet published
-	sources: ['foo', 'bar'],
-	names: ['foo', 'bar'],
-	mappings: 'foo',
-	file: 'foo'
+    version: (1 as any) as string, // Fixed by https://github.com/mozilla/source-map/pull/293 but the fix is not yet published
+    sources: ['foo', 'bar'],
+    names: ['foo', 'bar'],
+    mappings: 'foo',
+    file: 'foo',
 };
 store.registerMap('foo', sourceMap);
 
@@ -26,13 +26,12 @@ store.registerURL('foo', 'foo');
 
 const map = new CoverageMap({});
 const transformed = store.transformCoverage(map);
-transformed.map.data;
-transformed.sourceFinder('foo').trim();
+transformed.data;
 
 store.dispose();
 
 store.sourceStore.registerSource('foo', 'bar');
 const source = store.sourceStore.getSource('foo');
 if (source != null) {
-	source.trim();
+    source.trim();
 }