diff --git a/types/librato-node/index.d.ts b/types/librato-node/index.d.ts
index b34d0ff9c2..1e4571391c 100644
--- a/types/librato-node/index.d.ts
+++ b/types/librato-node/index.d.ts
@@ -26,6 +26,7 @@ export interface LibratoConfig {
     prefix?: string;
     source?: string;
     requestOptions?: LibratoRequestOptions;
+    period?: number;
     simulate?: false;
 }
 
diff --git a/types/librato-node/librato-node-tests.ts b/types/librato-node/librato-node-tests.ts
index 490214982e..eaf0609a74 100644
--- a/types/librato-node/librato-node-tests.ts
+++ b/types/librato-node/librato-node-tests.ts
@@ -26,6 +26,7 @@ librato.configure({
         method: 'POST',
         uri: 'https://foo.com',
     },
+    period: 5000,
     simulate: false,
 });