diff --git a/src/stdplus/fd/impl.hpp b/src/stdplus/fd/impl.hpp
index 0487aba..b4e134c 100644
--- a/src/stdplus/fd/impl.hpp
+++ b/src/stdplus/fd/impl.hpp
@@ -11,19 +11,20 @@
   public:
     virtual int get() const = 0;
 
-    span<std::byte> read(span<std::byte> buf) override;
-    span<std::byte> recv(span<std::byte> buf, RecvFlags flags) override;
-    span<const std::byte> write(span<const std::byte> data) override;
-    span<const std::byte> send(span<const std::byte> data,
-                               SendFlags flags) override;
+    std::span<std::byte> read(std::span<std::byte> buf) override;
+    std::span<std::byte> recv(std::span<std::byte> buf,
+                              RecvFlags flags) override;
+    std::span<const std::byte> write(std::span<const std::byte> data) override;
+    std::span<const std::byte> send(std::span<const std::byte> data,
+                                    SendFlags flags) override;
     size_t lseek(off_t offset, Whence whence) override;
     void truncate(off_t size) override;
-    void bind(span<const std::byte> sockaddr) override;
+    void bind(std::span<const std::byte> sockaddr) override;
     void listen(int backlog) override;
-    std::tuple<std::optional<int>, span<std::byte>>
-        accept(span<std::byte> sockaddr) override;
+    std::tuple<std::optional<int>, std::span<std::byte>>
+        accept(std::span<std::byte> sockaddr) override;
     void setsockopt(SockLevel level, SockOpt optname,
-                    span<const std::byte> opt) override;
+                    std::span<const std::byte> opt) override;
     int ioctl(unsigned long id, void* data) override;
     int constIoctl(unsigned long id, void* data) const override;
     void fcntlSetfd(FdFlags flags) override;