diff --git a/types/siema/index.d.ts b/types/siema/index.d.ts
index 834184a41e..d1b2c0d604 100644
--- a/types/siema/index.d.ts
+++ b/types/siema/index.d.ts
@@ -18,7 +18,7 @@ declare class Siema {
 }
 
 interface perPageInterface {
-  [key : number] : number;
+  [key: number]: number;
 }
 
 interface SiemaOptions {