diff --git a/types/istanbul/index.d.ts b/types/istanbul/index.d.ts
index ee23e27782..fe45802865 100644
--- a/types/istanbul/index.d.ts
+++ b/types/istanbul/index.d.ts
@@ -24,6 +24,7 @@ declare namespace istanbul {
     interface Collector {
         new (options?: any): Collector;
         add(coverage: any, testName?: string): void;
+        getFinalCoverage(): any;
     }
 
     interface Config {