diff --git a/spec.bs b/spec.bs
index dd610b8..b2bcd5e 100644
--- a/spec.bs
+++ b/spec.bs
@@ -317,15 +317,15 @@ observable.subscribe({}, {signal: outerController.signal});
 // SubscribeCallback is where the Observable "creator's" code lives. It's
 // called when subscribe() is called, to set up a new subscription.
 callback SubscribeCallback = undefined (Subscriber subscriber);
-callback SubscriptionObserverCallback = undefined (any value);
+callback ObservableSubscriptionCallback = undefined (any value);
 
 dictionary SubscriptionObserver {
-  SubscriptionObserverCallback next;
-  SubscriptionObserverCallback error;
+  ObservableSubscriptionCallback next;
+  ObservableSubscriptionCallback error;
   VoidFunction complete;
 };
 
-typedef (SubscriptionObserverCallback or SubscriptionObserver) ObserverUnion;
+typedef (ObservableSubscriptionCallback or SubscriptionObserver) ObserverUnion;
 
 dictionary SubscribeOptions {
   AbortSignal signal;
@@ -464,7 +464,7 @@ An <dfn>internal observer</dfn> is a [=struct=] with the following [=struct/item
        <ol id=process-observer>
          <li>
            <dl class="switch">
-             <dt>If |observer| is a {{SubscriptionObserverCallback}}</dt>
+             <dt>If |observer| is an {{ObservableSubscriptionCallback}}</dt>
              <dd>Set |internal observer|'s [=internal observer/next steps=] to these steps that take
                  an {{any}} |value|: