diff --git a/rtc/src/peer_connection/handler/datachannel.rs b/rtc/src/peer_connection/handler/datachannel.rs
index 260bea9..97f51a4 100644
--- a/rtc/src/peer_connection/handler/datachannel.rs
+++ b/rtc/src/peer_connection/handler/datachannel.rs
@@ -11,7 +11,7 @@ use crate::statistics::accumulator::RTCStatsAccumulator;
 use log::{debug, warn};
 use sctp::PayloadProtocolIdentifier;
 use shared::TransportContext;
-use shared::error::{Error, Result};
+use shared::error::{Error, Result, flatten_errs};
 use std::collections::{HashMap, VecDeque};
 use std::time::Instant;
 
@@ -329,6 +329,13 @@ impl<'a> sansio::Protocol<TaggedRTCMessageInternal, TaggedRTCMessageInternal, RT
     }
 
     fn close(&mut self) -> Result<()> {
-        Ok(())
+        let mut errs = vec![];
+        for dc in self.data_channels.values_mut() {
+            if let Err(e) = dc.close() {
+                errs.push(e);
+            }
+        }
+        self.data_channels.clear();
+        flatten_errs(errs)
     }
 }
diff --git a/rtc/src/peer_connection/handler/mod.rs b/rtc/src/peer_connection/handler/mod.rs
index f212fca..ea10c50 100644
--- a/rtc/src/peer_connection/handler/mod.rs
+++ b/rtc/src/peer_connection/handler/mod.rs
@@ -388,51 +388,16 @@ where
             handler.close()?;
         }));
 
+        // W3C WebRTC §close steps #4–#10 are implemented in individual handler close() methods:
+        //   InterceptorHandler::close() → interceptor.close()
+        //   DataChannelHandler::close() → closes all RTCDataChannelInternal instances
+        //   SctpHandler::close()        → closes all SCTP associations + endpoint
+        //   DtlsHandler::close()        → dtls_transport.stop()
+        //   IceHandler::close()         → ice_transport.agent.close()
+        //
+        // The for_each_handler!(forward: ...) loop above invokes each handler's close() in order.
         let close_errs: Vec<Error> = vec![];
 
-        /* TODO:
-        if let Err(err) = self.interceptor.close().await {
-            close_errs.push(Error::new(format!("interceptor: {err}")));
-        }
-
-        // https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close (step #4)
-        {
-            let mut rtp_transceivers = self.internal.rtp_transceivers.lock().await;
-            for t in &*rtp_transceivers {
-                if let Err(err) = t.stop().await {
-                    close_errs.push(Error::new(format!("rtp_transceivers: {err}")));
-                }
-            }
-            rtp_transceivers.clear();
-        }
-
-        // https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close (step #5)
-        {
-            let mut data_channels = self.internal.sctp_transport.data_channels.lock().await;
-            for d in &*data_channels {
-                if let Err(err) = d.close().await {
-                    close_errs.push(Error::new(format!("data_channels: {err}")));
-                }
-            }
-            data_channels.clear();
-        }
-
-        // https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close (step #6)
-        if let Err(err) = self.internal.sctp_transport.stop().await {
-            close_errs.push(Error::new(format!("sctp_transport: {err}")));
-        }
-
-        // https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close (step #7)
-        if let Err(err) = self.internal.dtls_transport.stop().await {
-            close_errs.push(Error::new(format!("dtls_transport: {err}")));
-        }
-
-        // https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-close (step #8, #9, #10)
-        if let Err(err) = self.internal.ice_transport.stop().await {
-            close_errs.push(Error::new(format!("ice_transport: {err}")));
-        }
-         */
-
         self.update_connection_state(true);
 
         flatten_errs(close_errs)
diff --git a/rtc/src/peer_connection/handler/sctp.rs b/rtc/src/peer_connection/handler/sctp.rs
index 8f1d4f4..6b3f804 100644
--- a/rtc/src/peer_connection/handler/sctp.rs
+++ b/rtc/src/peer_connection/handler/sctp.rs
@@ -12,8 +12,8 @@ use datachannel::message::Message;
 use datachannel::message::message_channel_threshold::DataChannelThreshold;
 use log::{debug, warn};
 use sctp::{
-    AssociationEvent, AssociationHandle, ClientConfig, DatagramEvent, EndpointEvent, Event,
-    Payload, PayloadProtocolIdentifier, StreamEvent,
+    AssociationError, AssociationEvent, AssociationHandle, ClientConfig, DatagramEvent,
+    EndpointEvent, Event, Payload, PayloadProtocolIdentifier, StreamEvent,
 };
 use shared::error::{Error, Result};
 use shared::marshal::Unmarshal;
@@ -467,7 +467,18 @@ impl<'a> sansio::Protocol<TaggedRTCMessageInternal, TaggedRTCMessageInternal, RT
     }
 
     fn close(&mut self) -> Result<()> {
-        Ok(())
+        // Close all SCTP associations and drain the endpoint so state machines shut down cleanly.
+        let sctp = &mut self.ctx.sctp_transport;
+        let mut errs = vec![];
+        for (_, assoc) in sctp.sctp_associations.iter_mut() {
+            if let Err(e) = assoc.close(AssociationError::LocallyClosed) {
+                errs.push(e);
+            }
+        }
+        sctp.sctp_associations.clear();
+        sctp.sctp_endpoint = None;
+
+        shared::error::flatten_errs(errs)
     }
 }