diff --git a/src/observable/BaseObservable.ts b/src/observable/BaseObservable.ts
index 1d774797..44d716ac 100644
--- a/src/observable/BaseObservable.ts
+++ b/src/observable/BaseObservable.ts
@@ -65,7 +65,7 @@ export abstract class BaseObservable<T> {
 
 export function tests() {
     class Collection extends BaseObservable<{}> {
-        firstSubscribeCalls: number= 0;
+        firstSubscribeCalls: number = 0;
         firstUnsubscribeCalls: number = 0;
 
         onSubscribeFirst() { this.firstSubscribeCalls += 1; }