diff --git a/proxyquire/proxyquire.d.ts b/proxyquire/proxyquire.d.ts
index 06e1c773e7..87254a0554 100644
--- a/proxyquire/proxyquire.d.ts
+++ b/proxyquire/proxyquire.d.ts
@@ -14,12 +14,12 @@ interface Proxyquire {
     noCallThru(): Proxyquire;
     callThru(): Proxyquire;
 
-    noPreserveCache(): void;
-    preserveCache(): void;
+    noPreserveCache(): Proxyquire;
+    preserveCache(): Proxyquire;
 }
 
 declare module 'proxyquire' {
 
     var p: Proxyquire;
     export = p;
-}
\ No newline at end of file
+}