diff --git a/features/netsocket/InternetSocket.cpp b/features/netsocket/InternetSocket.cpp
index a070757498..57d5a3c738 100644
--- a/features/netsocket/InternetSocket.cpp
+++ b/features/netsocket/InternetSocket.cpp
@@ -205,11 +205,6 @@ void InternetSocket::sigio(Callback<void()> callback)
     core_util_critical_section_exit();
 }
 
-void InternetSocket::attach(Callback<void()> callback)
-{
-    sigio(callback);
-}
-
 nsapi_error_t InternetSocket::getpeername(SocketAddress *address)
 {
     if (!_socket) {
diff --git a/features/netsocket/InternetSocket.h b/features/netsocket/InternetSocket.h
index b347c3e6e5..4ebe465e4c 100644
--- a/features/netsocket/InternetSocket.h
+++ b/features/netsocket/InternetSocket.h
@@ -124,33 +124,6 @@ public:
      */
     nsapi_error_t getpeername(SocketAddress *address) override;
 
-    /** Register a callback on state change of the socket.
-     *
-     *  @see Socket::sigio
-     *  @deprecated
-     *      The behavior of Socket::attach differs from other attach functions in
-     *      Mbed OS and has been known to cause confusion. Replaced by Socket::sigio.
-     */
-    MBED_DEPRECATED_SINCE("mbed-os-5.4",
-                          "The behavior of Socket::attach differs from other attach functions in "
-                          "Mbed OS and has been known to cause confusion. Replaced by Socket::sigio.")
-    void attach(mbed::Callback<void()> func);
-
-    /** Register a callback on state change of the socket.
-     *
-     *  @see Socket::sigio
-     *  @deprecated
-     *      The attach function does not support cv-qualifiers. Replaced by
-     *      attach(callback(obj, method)).
-     */
-    template <typename T, typename M>
-    MBED_DEPRECATED_SINCE("mbed-os-5.1",
-                          "The attach function does not support cv-qualifiers. Replaced by "
-                          "attach(callback(obj, method)).")
-    void attach(T *obj, M method)
-    {
-        attach(mbed::callback(obj, method));
-    }
 
 #if !defined(DOXYGEN_ONLY)