diff --git a/CHANGES.md b/CHANGES.md
index 346ab99c..444fbf42 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,10 @@
 
 * v5: Handle 16 concurrent control service requests
 
+* v3: Handle packet id in use for subscribe and unsubscribe packets
+
+* v3: Handle 16 concurrent control service requests
+
 ## [0.3.1] - 2020-08-12
 
 * v5: Fix max inflight check
diff --git a/Cargo.toml b/Cargo.toml
index 64fa23b8..ee5d7c14 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ntex-mqtt"
-version = "0.3.1"
+version = "0.3.2"
 authors = ["ntex contributors <team@ntex.rs>"]
 description = "MQTT Client/Server framework for v5 and v3.1.1 protocols"
 documentation = "https://docs.rs/ntex-mqtt"
diff --git a/src/v3/dispatcher.rs b/src/v3/dispatcher.rs
index 858ba42f..44c42b72 100644
--- a/src/v3/dispatcher.rs
+++ b/src/v3/dispatcher.rs
@@ -6,7 +6,6 @@ use futures::future::{err, join, ok, Either, FutureExt, Ready};
 use futures::ready;
 use fxhash::FxHashSet;
 use ntex::service::{fn_factory_with_config, Service, ServiceFactory};
-use ntex::util::buffer::BufferService;
 use ntex::util::inflight::InFlightService;
 use ntex::util::order::{InOrder, InOrderError};
 
@@ -65,11 +64,13 @@ where
                         InOrderError::Disconnected => MqttError::Disconnected,
                     }),
                 ),
-                BufferService::new(
+                // limit number of in-flight control messages
+                InFlightService::new(
                     16,
-                    || MqttError::Disconnected,
-                    // limit number of in-flight messages
-                    InFlightService::new(1, control?),
+                    InOrder::service(control?).map_err(|e| match e {
+                        InOrderError::Service(e) => e,
+                        InOrderError::Disconnected => MqttError::Disconnected,
+                    }),
                 ),
             ))
         }
@@ -145,6 +146,7 @@ where
                 // check for duplicated packet id
                 if let Some(pid) = packet_id {
                     if !inflight.borrow_mut().insert(pid) {
+                        log::trace!("Duplicated packet id for publish packet: {:?}", pid);
                         return Either::Right(Either::Left(err(MqttError::Protocol(
                             ProtocolError::DuplicatedPacketId,
                         ))));
@@ -161,27 +163,45 @@ where
                 self.session.sink().complete_publish_qos1(packet_id);
                 Either::Right(Either::Left(ok(None)))
             }
-            codec::Packet::PingRequest => Either::Right(Either::Right(ControlResponse {
-                fut: self.control.call(ControlPacket::ping()),
-            })),
-            codec::Packet::Disconnect => Either::Right(Either::Right(ControlResponse {
-                fut: self.control.call(ControlPacket::disconnect()),
-            })),
+            codec::Packet::PingRequest => Either::Right(Either::Right(ControlResponse::new(
+                self.control.call(ControlPacket::ping()),
+                &self.inflight,
+            ))),
+            codec::Packet::Disconnect => Either::Right(Either::Right(ControlResponse::new(
+                self.control.call(ControlPacket::disconnect()),
+                &self.inflight,
+            ))),
             codec::Packet::Subscribe { packet_id, topic_filters } => {
-                Either::Right(Either::Right(ControlResponse {
-                    fut: self.control.call(ControlPacket::Subscribe(Subscribe::new(
+                if !self.inflight.borrow_mut().insert(packet_id) {
+                    log::trace!("Duplicated packet id for unsubscribe packet: {:?}", packet_id);
+                    return Either::Right(Either::Left(err(MqttError::Protocol(
+                        ProtocolError::DuplicatedPacketId,
+                    ))));
+                }
+
+                Either::Right(Either::Right(ControlResponse::new(
+                    self.control.call(ControlPacket::Subscribe(Subscribe::new(
                         packet_id,
                         topic_filters,
                     ))),
-                }))
+                    &self.inflight,
+                )))
             }
             codec::Packet::Unsubscribe { packet_id, topic_filters } => {
-                Either::Right(Either::Right(ControlResponse {
-                    fut: self.control.call(ControlPacket::Unsubscribe(Unsubscribe::new(
+                if !self.inflight.borrow_mut().insert(packet_id) {
+                    log::trace!("Duplicated packet id for unsubscribe packet: {:?}", packet_id);
+                    return Either::Right(Either::Left(err(MqttError::Protocol(
+                        ProtocolError::DuplicatedPacketId,
+                    ))));
+                }
+
+                Either::Right(Either::Right(ControlResponse::new(
+                    self.control.call(ControlPacket::Unsubscribe(Unsubscribe::new(
                         packet_id,
                         topic_filters,
                     ))),
-                }))
+                    &self.inflight,
+                )))
             }
             _ => Either::Right(Either::Left(ok(None))),
         }
@@ -228,6 +248,16 @@ pin_project_lite::pin_project! {
     {
         #[pin]
         fut: T,
+        inflight: Rc<RefCell<FxHashSet<NonZeroU16>>>,
+    }
+}
+
+impl<T, E> ControlResponse<T, E>
+where
+    T: Future<Output = Result<ControlResult, MqttError<E>>>,
+{
+    fn new(fut: T, inflight: &Rc<RefCell<FxHashSet<NonZeroU16>>>) -> Self {
+        Self { fut, inflight: inflight.clone() }
     }
 }
 
@@ -238,13 +268,19 @@ where
     type Output = Result<Option<codec::Packet>, MqttError<E>>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let packet = match ready!(self.project().fut.poll(cx))?.result {
+        let this = self.project();
+
+        let packet = match ready!(this.fut.poll(cx))?.result {
             ControlResultKind::Ping => Some(codec::Packet::PingResponse),
-            ControlResultKind::Subscribe(res) => Some(codec::Packet::SubscribeAck {
-                status: res.codes,
-                packet_id: res.packet_id,
-            }),
+            ControlResultKind::Subscribe(res) => {
+                this.inflight.borrow_mut().remove(&res.packet_id);
+                Some(codec::Packet::SubscribeAck {
+                    status: res.codes,
+                    packet_id: res.packet_id,
+                })
+            }
             ControlResultKind::Unsubscribe(res) => {
+                this.inflight.borrow_mut().remove(&res.packet_id);
                 Some(codec::Packet::UnsubscribeAck { packet_id: res.packet_id })
             }
             ControlResultKind::Disconnect => None,
diff --git a/src/v5/dispatcher.rs b/src/v5/dispatcher.rs
index bfc93d7a..20c0e78c 100644
--- a/src/v5/dispatcher.rs
+++ b/src/v5/dispatcher.rs
@@ -68,16 +68,16 @@ where
                         io::Error::new(io::ErrorKind::Other, "Service dropped"),
                     )),
                 }),
-                InOrder::service(
-                    // limit number of in-flight control messages
-                    InFlightService::new(16, control?),
-                )
-                .map_err(|e| match e {
-                    InOrderError::Service(e) => either::Either::Left(e),
-                    InOrderError::Disconnected => either::Either::Right(ProtocolError::Io(
-                        io::Error::new(io::ErrorKind::Other, "Service dropped"),
-                    )),
-                }),
+                // limit number of in-flight control messages
+                InFlightService::new(
+                    16,
+                    InOrder::service(control?).map_err(|e| match e {
+                        InOrderError::Service(e) => either::Either::Left(e),
+                        InOrderError::Disconnected => either::Either::Right(ProtocolError::Io(
+                            io::Error::new(io::ErrorKind::Other, "Service dropped"),
+                        )),
+                    }),
+                ),
             ))
         }
     })