diff --git a/src/lease-manager.ts b/src/lease-manager.ts
index fdc0de141..32b1102cc 100644
--- a/src/lease-manager.ts
+++ b/src/lease-manager.ts
@@ -106,6 +106,8 @@ export class LeaseManager extends EventEmitter {
    * Adds a message to the inventory, kicking off the deadline extender if it
    * isn't already running.
    *
+   * @fires LeaseManager#full
+   *
    * @param {Message} message The message.
    * @private
    */
@@ -141,6 +143,10 @@ export class LeaseManager extends EventEmitter {
   }
   /**
    * Removes ALL messages from inventory, and returns the ones removed.
+   *
+   * @fires LeaseManager#free
+   * @fires LeaseManager#empty
+   *
    * @private
    */
   clear(): Message[] {
@@ -197,6 +203,7 @@ export class LeaseManager extends EventEmitter {
    * messages are left over.
    *
    * @fires LeaseManager#free
+   * @fires LeaseManager#empty
    *
    * @param {Message} message The message to remove.
    * @private
diff --git a/src/subscriber.ts b/src/subscriber.ts
index c12996862..1989e11d6 100644
--- a/src/subscriber.ts
+++ b/src/subscriber.ts
@@ -655,7 +655,7 @@ export class Message implements tracing.MessageWithAttributes {
  *     close() function.
  * @property {SubscriberCloseBehavior} [options.behavior] The behavior of the close operation.
  *     - NackImmediately: Sends nacks for all messages held by the client library, and
- *       wait for them to send.
+ *       wait for them to send. (default to match old behavior)
  *     - WaitForProcessing: Continues normal ack/nack and leasing processes until close
  *       to the timeout, then switches to NackImmediately behavior to close down.
  *     Use {@link SubscriberCloseBehaviors} for enum values.
@@ -970,9 +970,10 @@ export class Subscriber extends EventEmitter {
 
     const options = this._options.closeOptions;
 
-    // If no behavior is specified, default to Wait.
+    // If no behavior is specified, default to Nack. This most closely matches
+    // the old behavior.
     const behavior =
-      options?.behavior ?? SubscriberCloseBehaviors.WaitForProcessing;
+      options?.behavior ?? SubscriberCloseBehaviors.NackImmediately;
 
     // The timeout can't realistically be longer than the longest time we're willing
     // to lease messages.
@@ -1000,7 +1001,7 @@ export class Subscriber extends EventEmitter {
     const shutdownStart = Date.now();
     if (
       behavior === SubscriberCloseBehaviors.WaitForProcessing &&
-      !this._inventory.isEmpty
+      !this._inventory.isEmpty()
     ) {
       const waitTimeout = timeout.subtract(FINAL_NACK_TIMEOUT);
 
diff --git a/system-test/pubsub.ts b/system-test/pubsub.ts
index 82bff2aa3..1729fe5bc 100644
--- a/system-test/pubsub.ts
+++ b/system-test/pubsub.ts
@@ -429,8 +429,8 @@ describe('pubsub', () => {
     const SUB_NAMES = [generateSubName(), generateSubName()];
     const SUB_DETACH_NAME = generateSubForDetach();
 
-    const thirty = Duration.from({minutes: 30});
-    const sixty = Duration.from({minutes: 60});
+    const thirty = Duration.from({seconds: 30});
+    const sixty = Duration.from({seconds: 60});
     const SUBSCRIPTIONS = [
       topic.subscription(SUB_NAMES[0], {minAckDeadline: thirty, maxAckDeadline: thirty}),
       topic.subscription(SUB_NAMES[1], {minAckDeadline: sixty, maxAckDeadline: sixty}),
@@ -659,9 +659,9 @@ describe('pubsub', () => {
 
       subscription.on('error', done);
 
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      subscription.on('message', (message: {data: any}) => {
+      subscription.on('message', message => {
         assert.deepStrictEqual(message.data, Buffer.from('hello'));
+        message.ack();
 
         if (++messageCount === 10) {
           subscription.close(done);
diff --git a/test/subscriber.ts b/test/subscriber.ts
index 4e6917b15..fce888a4e 100644
--- a/test/subscriber.ts
+++ b/test/subscriber.ts
@@ -106,7 +106,7 @@ class FakeLeaseManager extends EventEmitter {
   remove(message: s.Message): void {}
 
   _isEmpty = true;
-  get isEmpty() {
+  isEmpty(): boolean {
     return this._isEmpty;
   }
 }