diff --git a/dev/src/pool.ts b/dev/src/pool.ts
index 1e2d51123..3d417d8db 100644
--- a/dev/src/pool.ts
+++ b/dev/src/pool.ts
@@ -68,7 +68,7 @@ export class ClientPool<T> {
    */
   private acquire(requestTag: string): T {
     let selectedClient: T | null = null;
-    let selectedClientRequestCount = 0;
+    let selectedClientRequestCount = -1;
 
     for (const [client, requestCount] of this.activeClients) {
       // Use the "most-full" client that can still accommodate the request
@@ -99,6 +99,7 @@ export class ClientPool<T> {
     } else {
       logger('ClientPool.acquire', requestTag, 'Creating a new client');
       selectedClient = this.clientFactory();
+      selectedClientRequestCount = 0;
       assert(
         !this.activeClients.has(selectedClient),
         'The provided client factory returned an existing instance'
diff --git a/dev/test/pool.ts b/dev/test/pool.ts
index 0ff986a4f..dfa658e6f 100644
--- a/dev/test/pool.ts
+++ b/dev/test/pool.ts
@@ -51,7 +51,7 @@ describe('Client pool', () => {
     expect(clientPool.size).to.equal(2);
   });
 
-  it('re-uses idle instances', () => {
+  it('re-uses instances with remaining capacity', () => {
     const clientPool = new ClientPool<{}>(2, 0, () => {
       return {};
     });
@@ -80,6 +80,34 @@ describe('Client pool', () => {
     });
   });
 
+  it('re-uses idle instances', async () => {
+    let instanceCount = 0;
+    const clientPool = new ClientPool<{}>(1, 1, () => {
+      ++instanceCount;
+      return {};
+    });
+
+    const operationPromises = deferredPromises(2);
+
+    let completionPromise = clientPool.run(
+      REQUEST_TAG,
+      () => operationPromises[0].promise
+    );
+    expect(clientPool.size).to.equal(1);
+    operationPromises[0].resolve();
+    await completionPromise;
+
+    completionPromise = clientPool.run(
+      REQUEST_TAG,
+      () => operationPromises[1].promise
+    );
+    expect(clientPool.size).to.equal(1);
+    operationPromises[1].resolve();
+    await completionPromise;
+
+    expect(instanceCount).to.equal(1);
+  });
+
   it('bin packs operations', async () => {
     let clientCount = 0;
     const clientPool = new ClientPool<number>(2, 0, () => {