diff --git a/src/Client.php b/src/Client.php
index cb33c66..a9eb709 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -331,8 +331,10 @@ private function disconnect(
             return;
         }
 
+        [$subscribers, $this->subscribers] = [$this->subscribers, []];
+
         /** @var ?Subscription $subscription */
-        foreach ($this->subscribers as [$_, $subscription]) {
+        foreach ($subscribers as [$_, $subscription]) {
             if ($subscription !== null) {
                 $do($subscription);
             }
diff --git a/src/Exception/ConnectionWasClosed.php b/src/Exception/ConnectionWasClosed.php
new file mode 100644
index 0000000..1960f78
--- /dev/null
+++ b/src/Exception/ConnectionWasClosed.php
@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Thesis\Nats\Exception;
+
+use Thesis\Nats\NatsException;
+
+/**
+ * @api
+ */
+final class ConnectionWasClosed extends NatsException {}
diff --git a/src/Internal/Connection/SocketConnection.php b/src/Internal/Connection/SocketConnection.php
index 0a4236c..f0f647e 100644
--- a/src/Internal/Connection/SocketConnection.php
+++ b/src/Internal/Connection/SocketConnection.php
@@ -165,17 +165,13 @@ private function run(): void
                             $deferred->complete($frame);
                         }
                     }
-
-                    return;
                 } catch (\Throwable $e) {
                     foreach ($queue as $deferred) {
                         $deferred->error($e);
                     }
-
+                } finally {
                     $running = false;
                     $hooks->dispatch(Hooks\ConnectionClosed::Event);
-
-                    return;
                 }
             }
         });
diff --git a/src/Internal/Protocol/decodeHeaders.php b/src/Internal/Protocol/decodeHeaders.php
index d8094c6..7cc6523 100644
--- a/src/Internal/Protocol/decodeHeaders.php
+++ b/src/Internal/Protocol/decodeHeaders.php
@@ -38,7 +38,7 @@ function decodeHeaders(string $encoded): Headers
     }
 
     foreach ($lines as $line) {
-        $keypair = explode(': ', $line);
+        $keypair = explode(': ', $line, limit: 2);
         if (\count($keypair) !== 2) {
             throw new \InvalidArgumentException(\sprintf('Invalid msg header line "%s" received.', $line));
         }
diff --git a/src/Internal/Rpc/Handler.php b/src/Internal/Rpc/Handler.php
index 5e9e51a..2d8936f 100644
--- a/src/Internal/Rpc/Handler.php
+++ b/src/Internal/Rpc/Handler.php
@@ -9,6 +9,7 @@
 use Amp\Future;
 use Thesis\Nats\Client;
 use Thesis\Nats\Delivery;
+use Thesis\Nats\Exception\ConnectionWasClosed;
 use Thesis\Nats\Exception\RequestHasNoResponders;
 use Thesis\Nats\Header\StatusCode;
 use Thesis\Nats\Internal\Id;
@@ -20,8 +21,8 @@
  */
 final class Handler
 {
-    /** @var array<non-empty-string, callable(Delivery): void> */
-    private array $futures = [];
+    /** @var array<non-empty-string, PendingRequest> */
+    private array $pendings = [];
 
     /** @var non-empty-string */
     private readonly string $inboxId;
@@ -40,21 +41,24 @@ public function __construct()
      */
     public function setup(\Closure $subscribe, ?Cancellation $cancellation = null): void
     {
-        $futures = &$this->futures;
+        $pendings = &$this->pendings;
         $inboxId = $this->inboxId;
 
         $this->unsubscribe = $subscribe(
             "{$inboxId}*",
             static function (Delivery $delivery) use (
-                &$futures,
+                &$pendings,
                 $inboxId,
             ): void {
                 $replyTo = ReplyTo::parse($inboxId, $delivery->subject);
 
                 try {
-                    ($futures[$replyTo->token] ?? static fn() => null)($delivery);
+                    $pending = $pendings[$replyTo->token] ?? null;
+                    if ($pending !== null) {
+                        $pending($delivery);
+                    }
                 } finally {
-                    unset($futures[$replyTo->token]);
+                    unset($pendings[$replyTo->token]);
                 }
             },
             $cancellation,
@@ -63,13 +67,17 @@ static function (Delivery $delivery) use (
 
     public function shutdown(?Cancellation $cancellation = null): void
     {
-        try {
-            if ($this->unsubscribe !== null) {
-                ($this->unsubscribe)($cancellation);
-            }
-        } finally {
-            $this->unsubscribe = null;
-            $this->futures = [];
+        [$pendings, $this->pendings] = [$this->pendings, []];
+
+        $e = new ConnectionWasClosed();
+
+        foreach ($pendings as $pending) {
+            $pending->deferred->error($e);
+        }
+
+        [$unsubscribe, $this->unsubscribe] = [$this->unsubscribe, null];
+        if ($unsubscribe !== null) {
+            $unsubscribe($cancellation);
         }
     }
 
@@ -86,13 +94,16 @@ public function request(
 
         /** @var DeferredFuture<Delivery> $deferred */
         $deferred = new DeferredFuture();
-        $this->futures[$replyTo->token] = static function (Delivery $delivery) use ($deferred): void {
-            if ($delivery->message->headers?->get(StatusCode::Header) === Status::NoResponders) {
-                $deferred->error(new RequestHasNoResponders());
-            } else {
-                $deferred->complete($delivery);
-            }
-        };
+        $this->pendings[$replyTo->token] = new PendingRequest(
+            handle: static function (Delivery $delivery) use ($deferred): void {
+                if ($delivery->message->headers?->get(StatusCode::Header) === Status::NoResponders) {
+                    $deferred->error(new RequestHasNoResponders());
+                } else {
+                    $deferred->complete($delivery);
+                }
+            },
+            deferred: $deferred,
+        );
 
         $client->publish($subject, $message, $replyTo->subject);
 
diff --git a/src/Internal/Rpc/PendingRequest.php b/src/Internal/Rpc/PendingRequest.php
new file mode 100644
index 0000000..e9912e9
--- /dev/null
+++ b/src/Internal/Rpc/PendingRequest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Thesis\Nats\Internal\Rpc;
+
+use Amp\DeferredFuture;
+use Thesis\Nats\Delivery;
+
+/**
+ * @internal
+ */
+final readonly class PendingRequest
+{
+    /**
+     * @param \Closure(Delivery): void $handle
+     * @param DeferredFuture<Delivery> $deferred
+     */
+    public function __construct(
+        public \Closure $handle,
+        public DeferredFuture $deferred,
+    ) {}
+
+    public function __invoke(Delivery $delivery): void
+    {
+        ($this->handle)($delivery);
+    }
+}
diff --git a/tests/Internal/Protocol/HeadersTest.php b/tests/Internal/Protocol/HeadersTest.php
index 7295e1a..abf43bc 100644
--- a/tests/Internal/Protocol/HeadersTest.php
+++ b/tests/Internal/Protocol/HeadersTest.php
@@ -44,6 +44,10 @@ final class HeadersTest extends TestCase
         new Headers(['X' => ['Y'], StatusCode::Header->value => ['100'], StatusDescription::Header->value => ['idle heartbeat']]),
         "NATS/1.0 100 idle heartbeat\r\nX: Y\r\n\r\n",
     ])]
+    #[TestWith([
+        new Headers(['Bar' => ['Baz: Foo']]),
+        "NATS/1.0\r\nBar: Baz: Foo\r\n\r\n",
+    ])]
     public function testEncode(Headers $headers, string $encoded): void
     {
         self::assertEquals($encoded, encodeHeaders($headers));