diff --git a/asio/include/asio/experimental/detail/channel_service.hpp b/asio/include/asio/experimental/detail/channel_service.hpp
index 38df2595d7..1232441461 100644
--- a/asio/include/asio/experimental/detail/channel_service.hpp
+++ b/asio/include/asio/experimental/detail/channel_service.hpp
@@ -83,7 +83,7 @@ class channel_service
   struct implementation_type;
 
   // Constructor.
-  channel_service(execution_context& ctx);
+  channel_service(asio::execution_context& ctx);
 
   // Destroy all user-defined handler objects owned by the service.
   void shutdown();
diff --git a/asio/include/asio/experimental/detail/impl/channel_service.hpp b/asio/include/asio/experimental/detail/impl/channel_service.hpp
index c6a69a98f0..797c9f433c 100644
--- a/asio/include/asio/experimental/detail/impl/channel_service.hpp
+++ b/asio/include/asio/experimental/detail/impl/channel_service.hpp
@@ -22,7 +22,8 @@ namespace experimental {
 namespace detail {
 
 template <typename Mutex>
-inline channel_service<Mutex>::channel_service(execution_context& ctx)
+inline channel_service<Mutex>::channel_service(
+    asio::execution_context& ctx)
   : asio::detail::execution_context_service_base<channel_service>(ctx),
     mutex_(),
     impl_list_(0)