diff --git a/clientv3/integration/kv_test.go b/clientv3/integration/kv_test.go
index <HASH>..<HASH> 100644
--- a/clientv3/integration/kv_test.go
+++ b/clientv3/integration/kv_test.go
@@ -37,8 +37,8 @@ func TestKVPutError(t *testing.T) {
 	defer testutil.AfterTest(t)
 
 	var (
-		maxReqBytes = 1.5 * 1024 * 1024 // hard coded max in v3_server.go
-		quota       = int64(int(maxReqBytes) + 8*os.Getpagesize())
+		maxReqBytes = 1.5 * 1024 * 1024                                // hard coded max in v3_server.go
+		quota       = int64(int(maxReqBytes*1.2) + 8*os.Getpagesize()) // make sure we have enough overhead in backend quota. See discussion in #6486.
 	)
 	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 1, QuotaBackendBytes: quota, ClientMaxCallSendMsgSize: 100 * 1024 * 1024})
 	defer clus.Terminate(t)
integration: fix TestKVPutError

Give backend quota enough overhead.