diff --git a/include/async_mqtt5/impl/connect_op.hpp b/include/async_mqtt5/impl/connect_op.hpp
index 083e299..50013a9 100644
--- a/include/async_mqtt5/impl/connect_op.hpp
+++ b/include/async_mqtt5/impl/connect_op.hpp
@@ -2,6 +2,7 @@
 #define ASYNC_MQTT5_CONNECT_OP_HPP
 
 #include <boost/asio/append.hpp>
+#include <boost/asio/cancellation_state.hpp>
 #include <boost/asio/consign.hpp>
 #include <boost/asio/dispatch.hpp>
 #include <boost/asio/prepend.hpp>
@@ -48,6 +49,7 @@ class connect_op {
 	handler_type _handler;
 
 	std::unique_ptr<std::string> _buffer_ptr;
+	asio::cancellation_state _cancellation_state;
 
 	using endpoint = asio::ip::tcp::endpoint;
 	using epoints = asio::ip::tcp::resolver::results_type;
@@ -58,7 +60,12 @@ public:
 		Stream& stream, Handler&& handler, mqtt_ctx& ctx
 	) :
 		_stream(stream), _ctx(ctx),
-		_handler(std::forward<Handler>(handler))
+		_handler(std::forward<Handler>(handler)),
+		_cancellation_state(
+			asio::get_associated_cancellation_slot(_handler),
+			asio::enable_total_cancellation{},
+			asio::enable_total_cancellation{}
+		)
 	{}
 
 	connect_op(connect_op&&) noexcept = default;
@@ -77,7 +84,7 @@ public:
 	using cancellation_slot_type =
 		asio::associated_cancellation_slot_t<handler_type>;
 	cancellation_slot_type get_cancellation_slot() const noexcept {
-		return asio::get_associated_cancellation_slot(_handler);
+		return _cancellation_state.slot();
 	}
 
 	void perform(
@@ -95,6 +102,9 @@ public:
 	void operator()(
 		on_connect, error_code ec, endpoint ep, authority_path ap
 	) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -130,6 +140,9 @@ public:
 		on_tls_handshake, error_code ec,
 		endpoint ep, authority_path ap
 	) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -168,6 +181,9 @@ public:
 	}
 
 	void operator()(on_ws_handshake, error_code ec) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -184,6 +200,9 @@ public:
 	}
 
 	void operator()(on_init_auth_data, error_code ec, std::string data) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(asio::error::try_again);
 
@@ -212,6 +231,9 @@ public:
 	}
 
 	void operator()(on_send_connect, error_code ec, size_t) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -227,6 +249,9 @@ public:
 	void operator()(
 		on_fixed_header, error_code ec, size_t num_read
 	) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -267,6 +292,9 @@ public:
 		on_read_packet, error_code ec, size_t, control_code_e code,
 		byte_citer first, byte_citer last
 	) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -336,6 +364,9 @@ public:
 	}
 
 	void operator()(on_auth_data, error_code ec, std::string data) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(asio::error::try_again);
 
@@ -362,6 +393,9 @@ public:
 	}
 
 	void operator()(on_send_auth, error_code ec, size_t) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(ec);
 
@@ -373,6 +407,9 @@ public:
 	}
 
 	void operator()(on_complete_auth, error_code ec, std::string) {
+		if (is_cancelled())
+			return complete(asio::error::operation_aborted);
+
 		if (ec)
 			return complete(asio::error::try_again);
 
@@ -380,7 +417,12 @@ public:
 	}
 
 private:
+	bool is_cancelled() const {
+		return _cancellation_state.cancelled() != asio::cancellation_type::none;
+	}
+
 	void complete(error_code ec) {
+		_cancellation_state.slot().clear();
 		std::move(_handler)(ec);
 	}
 
diff --git a/test/include/test_common/delayed_op.hpp b/test/include/test_common/delayed_op.hpp
index 1f15a84..bfb4bd4 100644
--- a/test/include/test_common/delayed_op.hpp
+++ b/test/include/test_common/delayed_op.hpp
@@ -70,6 +70,12 @@ public:
 
 	template <typename CompletionHandler>
 	void operator()(on_timer, CompletionHandler&& h, error_code ec) {
+		// The timer places a handler into the cancellation slot
+		// and does not clear it. Therefore, we need to clear it explicitly
+		// to properly remove the corresponding cancellation signal
+		// in the test_broker.
+		get_cancellation_slot().clear();
+
 		auto bh = std::apply(
 			[h = std::move(h)](auto&&... args) mutable {
 				return asio::append(std::move(h), std::move(args)...);