diff --git a/configure b/configure
index caaf1a490b77..8760f1c9988a 100755
--- a/configure
+++ b/configure
@@ -18431,13 +18431,15 @@ fi
 
 ## socklen_t
 
-case $host in #(
+case $target in #(
   *-*-mingw32*|*-pc-windows) :
     ac_fn_c_check_type "$LINENO" "socklen_t" "ac_cv_type_socklen_t" "#include <ws2tcpip.h>
 "
 if test "x$ac_cv_type_socklen_t" = xyes
 then :
-  printf "%s\n" "#define HAS_SOCKLEN_T 1" >>confdefs.h
+
+printf "%s\n" "#define HAVE_SOCKLEN_T 1" >>confdefs.h
+
 
 fi
  ;; #(
@@ -18446,7 +18448,9 @@ fi
 "
 if test "x$ac_cv_type_socklen_t" = xyes
 then :
-  printf "%s\n" "#define HAS_SOCKLEN_T 1" >>confdefs.h
+
+printf "%s\n" "#define HAVE_SOCKLEN_T 1" >>confdefs.h
+
 
 fi
  ;;
diff --git a/configure.ac b/configure.ac
index 7201a8eb2c94..26af082473ed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1969,12 +1969,10 @@ AS_IF([$sockets], [AC_DEFINE([HAS_SOCKETS], [1])])
 
 ## socklen_t
 
-AS_CASE([$host],
+AS_CASE([$target],
   [*-*-mingw32*|*-pc-windows],
-    [AC_CHECK_TYPE([socklen_t], [AC_DEFINE([HAS_SOCKLEN_T], [1])], [],
-      [#include <ws2tcpip.h>])],
-  [AC_CHECK_TYPE([socklen_t], [AC_DEFINE([HAS_SOCKLEN_T], [1])], [],
-    [#include <sys/socket.h>])])
+    [AC_CHECK_TYPES([socklen_t], [], [], [#include <ws2tcpip.h>])],
+  [AC_CHECK_TYPES([socklen_t], [], [], [#include <sys/socket.h>])])
 
 AC_CHECK_FUNC([inet_aton], [AC_DEFINE([HAS_INET_ATON], [1])])
 
diff --git a/otherlibs/unix/accept_unix.c b/otherlibs/unix/accept_unix.c
index 482142354e79..f2724ee1feb3 100644
--- a/otherlibs/unix/accept_unix.c
+++ b/otherlibs/unix/accept_unix.c
@@ -32,7 +32,7 @@ CAMLprim value caml_unix_accept(value cloexec, value sock)
   int retcode;
   value res;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
   int clo = caml_unix_cloexec_p(cloexec);
 
   addr_len = sizeof(addr);
diff --git a/otherlibs/unix/accept_win32.c b/otherlibs/unix/accept_win32.c
index 8d747c57d1dd..569eb43d300b 100644
--- a/otherlibs/unix/accept_win32.c
+++ b/otherlibs/unix/accept_win32.c
@@ -28,7 +28,7 @@ CAMLprim value caml_unix_accept(value cloexec, value sock)
   SOCKET snew;
   value res;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
   DWORD err = 0;
 
   addr_len = sizeof(addr);
diff --git a/otherlibs/unix/bind_unix.c b/otherlibs/unix/bind_unix.c
index 9ea36c9e7250..620f286f95a2 100644
--- a/otherlibs/unix/bind_unix.c
+++ b/otherlibs/unix/bind_unix.c
@@ -25,7 +25,7 @@ CAMLprim value caml_unix_bind(value socket, value address)
 {
   int ret;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   caml_unix_get_sockaddr(address, &addr, &addr_len);
   ret = bind(Int_val(socket), (struct sockaddr *) &addr, addr_len);
diff --git a/otherlibs/unix/bind_win32.c b/otherlibs/unix/bind_win32.c
index 71e5b7a0255d..eba4325619f3 100644
--- a/otherlibs/unix/bind_win32.c
+++ b/otherlibs/unix/bind_win32.c
@@ -21,7 +21,7 @@ CAMLprim value caml_unix_bind(value socket, value address)
 {
   int ret;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   caml_unix_get_sockaddr(address, &addr, &addr_len);
   ret = bind(Socket_val(socket), (struct sockaddr *) &addr, addr_len);
diff --git a/otherlibs/unix/caml/socketaddr.h b/otherlibs/unix/caml/socketaddr.h
index 62e739b630f7..051e8046b294 100644
--- a/otherlibs/unix/caml/socketaddr.h
+++ b/otherlibs/unix/caml/socketaddr.h
@@ -55,11 +55,11 @@ union sock_addr_union {
 #endif
 };
 
-#ifdef HAS_SOCKLEN_T
-typedef socklen_t socklen_param_type;
-#else
-typedef int socklen_param_type;
+#ifndef HAVE_SOCKLEN_T
+typedef int socklen_t;
 #endif
+/* Deprecated: use socklen_t */
+CAMLdeprecated_typedef(socklen_param_type, socklen_t);
 
 #ifdef __cplusplus
 extern "C" {
@@ -74,9 +74,9 @@ extern "C" {
 
 extern void caml_unix_get_sockaddr (value vaddr,
                                struct sockaddr_storage * addr /*out*/,
-                               socklen_param_type * addr_len /*out*/);
+                               socklen_t * addr_len /*out*/);
 extern value caml_unix_alloc_sockaddr (struct sockaddr_storage * addr /*in*/,
-                                  socklen_param_type addr_len,
+                                  socklen_t addr_len,
                                   int close_on_error);
 extern value caml_unix_alloc_inet_addr (struct in_addr * inaddr);
 #define GET_INET_ADDR(v) (*((struct in_addr *) (v)))
diff --git a/otherlibs/unix/channels_unix.c b/otherlibs/unix/channels_unix.c
index 152ba6ac6b95..2921dcd6a394 100644
--- a/otherlibs/unix/channels_unix.c
+++ b/otherlibs/unix/channels_unix.c
@@ -46,7 +46,7 @@ static int caml_unix_check_stream_semantics(int fd)
 #ifdef HAS_SOCKETS
   case S_IFSOCK: {
     int so_type;
-    socklen_param_type so_type_len = sizeof(so_type);
+    socklen_t so_type_len = sizeof(so_type);
     if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &so_type, &so_type_len) == -1)
       return errno;
     switch (so_type) {
diff --git a/otherlibs/unix/connect_unix.c b/otherlibs/unix/connect_unix.c
index 0058268b9318..745d055943a7 100644
--- a/otherlibs/unix/connect_unix.c
+++ b/otherlibs/unix/connect_unix.c
@@ -26,7 +26,7 @@ CAMLprim value caml_unix_connect(value socket, value address)
 {
   int retcode;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   caml_unix_get_sockaddr(address, &addr, &addr_len);
   caml_enter_blocking_section();
diff --git a/otherlibs/unix/connect_win32.c b/otherlibs/unix/connect_win32.c
index 21ebdae79784..a4393a4609b4 100644
--- a/otherlibs/unix/connect_win32.c
+++ b/otherlibs/unix/connect_win32.c
@@ -22,7 +22,7 @@ CAMLprim value caml_unix_connect(value socket, value address)
 {
   SOCKET s = Socket_val(socket);
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
   DWORD err = 0;
 
   caml_unix_get_sockaddr(address, &addr, &addr_len);
diff --git a/otherlibs/unix/getaddrinfo.c b/otherlibs/unix/getaddrinfo.c
index f3a6bcbf8485..4313e1ca3d5e 100644
--- a/otherlibs/unix/getaddrinfo.c
+++ b/otherlibs/unix/getaddrinfo.c
@@ -39,7 +39,7 @@ static value convert_addrinfo(const struct addrinfo * a)
   CAMLparam0();
   CAMLlocal3(vres,vaddr,vcanonname);
   struct sockaddr_storage addr;
-  socklen_param_type len;
+  socklen_t len;
 
   len = a->ai_addrlen;
   if (len > sizeof(addr)) len = sizeof(addr);
diff --git a/otherlibs/unix/getnameinfo.c b/otherlibs/unix/getnameinfo.c
index 418484bcdcae..ec9ceb63d047 100644
--- a/otherlibs/unix/getnameinfo.c
+++ b/otherlibs/unix/getnameinfo.c
@@ -38,7 +38,7 @@ CAMLprim value caml_unix_getnameinfo(value vaddr, value vopts)
   CAMLparam0();
   CAMLlocal3(vhost, vserv, vres);
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
   char host[4096];
   char serv[1024];
   int opts, retcode;
diff --git a/otherlibs/unix/getpeername_unix.c b/otherlibs/unix/getpeername_unix.c
index 51d3c3fd6ac9..85e7662d42fa 100644
--- a/otherlibs/unix/getpeername_unix.c
+++ b/otherlibs/unix/getpeername_unix.c
@@ -25,7 +25,7 @@ CAMLprim value caml_unix_getpeername(value sock)
 {
   int retcode;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   addr_len = sizeof(addr);
   retcode = getpeername(Int_val(sock), (struct sockaddr *) &addr, &addr_len);
diff --git a/otherlibs/unix/getpeername_win32.c b/otherlibs/unix/getpeername_win32.c
index 01c659ae9c52..3ad2846e69ff 100644
--- a/otherlibs/unix/getpeername_win32.c
+++ b/otherlibs/unix/getpeername_win32.c
@@ -21,7 +21,7 @@ CAMLprim value caml_unix_getpeername(value sock)
 {
   int retcode;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   addr_len = sizeof(addr);
   retcode = getpeername(Socket_val(sock), (struct sockaddr *) &addr, &addr_len);
diff --git a/otherlibs/unix/getsockname_unix.c b/otherlibs/unix/getsockname_unix.c
index d1743f808381..b1073c62242d 100644
--- a/otherlibs/unix/getsockname_unix.c
+++ b/otherlibs/unix/getsockname_unix.c
@@ -25,7 +25,7 @@ CAMLprim value caml_unix_getsockname(value sock)
 {
   int retcode;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   addr_len = sizeof(addr);
   retcode = getsockname(Int_val(sock), (struct sockaddr *) &addr, &addr_len);
diff --git a/otherlibs/unix/getsockname_win32.c b/otherlibs/unix/getsockname_win32.c
index 19a2d6f8d2b6..a8619be8fcad 100644
--- a/otherlibs/unix/getsockname_win32.c
+++ b/otherlibs/unix/getsockname_win32.c
@@ -21,7 +21,7 @@ CAMLprim value caml_unix_getsockname(value sock)
 {
   int retcode;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   addr_len = sizeof(addr);
   retcode = getsockname(Socket_val(sock), (struct sockaddr *) &addr, &addr_len);
diff --git a/otherlibs/unix/sendrecv_unix.c b/otherlibs/unix/sendrecv_unix.c
index c1335d5d4ffa..0cca66e6748a 100644
--- a/otherlibs/unix/sendrecv_unix.c
+++ b/otherlibs/unix/sendrecv_unix.c
@@ -57,7 +57,7 @@ CAMLprim value caml_unix_recvfrom(value sock, value buff, value ofs, value len,
   char iobuf[UNIX_BUFFER_SIZE];
   value res;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   cv_flags = caml_convert_flag_list(flags, msg_flag_table);
   numbytes = Long_val(len);
@@ -101,7 +101,7 @@ CAMLprim value caml_unix_sendto_native(value sock, value buff, value ofs,
   long numbytes;
   char iobuf[UNIX_BUFFER_SIZE];
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
 
   cv_flags = caml_convert_flag_list(flags, msg_flag_table);
   caml_unix_get_sockaddr(dest, &addr, &addr_len);
diff --git a/otherlibs/unix/sendrecv_win32.c b/otherlibs/unix/sendrecv_win32.c
index 1b409d5e6934..8c21ea2286ca 100644
--- a/otherlibs/unix/sendrecv_win32.c
+++ b/otherlibs/unix/sendrecv_win32.c
@@ -61,7 +61,7 @@ CAMLprim value caml_unix_recvfrom(value sock, value buff, value ofs, value len,
   char iobuf[UNIX_BUFFER_SIZE];
   value res;
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
   DWORD err = 0;
 
   numbytes = Long_val(len);
@@ -117,7 +117,7 @@ value caml_unix_sendto_native(value sock, value buff, value ofs, value len,
   intnat numbytes;
   char iobuf[UNIX_BUFFER_SIZE];
   struct sockaddr_storage addr;
-  socklen_param_type addr_len;
+  socklen_t addr_len;
   DWORD err = 0;
 
   caml_unix_get_sockaddr(dest, &addr, &addr_len);
diff --git a/otherlibs/unix/socketaddr.c b/otherlibs/unix/socketaddr.c
index d3028bfe7376..3fd4ef393aa5 100644
--- a/otherlibs/unix/socketaddr.c
+++ b/otherlibs/unix/socketaddr.c
@@ -51,7 +51,7 @@ CAMLexport value caml_unix_alloc_inet6_addr(struct in6_addr * a)
 
 void caml_unix_get_sockaddr(value vaddr,
                        struct sockaddr_storage * addr /*out*/,
-                       socklen_param_type * addr_len /*out*/)
+                       socklen_t * addr_len /*out*/)
 {
   switch(Tag_val(vaddr)) {
   case 0:                       /* ADDR_UNIX */
@@ -109,7 +109,7 @@ static value alloc_unix_sockaddr(value path) {
 }
 
 value caml_unix_alloc_sockaddr(struct sockaddr_storage * addr /*in*/,
-                          socklen_param_type addr_len, int close_on_error)
+                          socklen_t addr_len, int close_on_error)
 {
   CAMLparam0();
   CAMLlocal1(a);
diff --git a/otherlibs/unix/socketpair_win32.c b/otherlibs/unix/socketpair_win32.c
index acb4cb74dde4..e2c775e1e869 100644
--- a/otherlibs/unix/socketpair_win32.c
+++ b/otherlibs/unix/socketpair_win32.c
@@ -40,7 +40,7 @@ static int socketpair(int domain, int type, int protocol,
 {
   wchar_t dirname[MAX_PATH + 1], path[MAX_PATH + 1];
   struct sockaddr_un addr;
-  socklen_param_type socklen;
+  socklen_t socklen;
 
   /* POSIX states that in case of error, the contents of socket_vector
      shall be unmodified. */
diff --git a/otherlibs/unix/sockopt_unix.c b/otherlibs/unix/sockopt_unix.c
index a826de86ba05..29011acfc9fe 100644
--- a/otherlibs/unix/sockopt_unix.c
+++ b/otherlibs/unix/sockopt_unix.c
@@ -180,7 +180,7 @@ CAMLexport value caml_unix_getsockopt_aux(const char * name,
   CAMLlocal1(err);
   value res;
   union option_value optval;
-  socklen_param_type optsize;
+  socklen_t optsize;
 
 
   switch (ty) {
@@ -235,7 +235,7 @@ CAMLexport value caml_unix_setsockopt_aux(const char * name,
                                      value socket, value val)
 {
   union option_value optval;
-  socklen_param_type optsize;
+  socklen_t optsize;
   double f;
 
   switch (ty) {
diff --git a/otherlibs/unix/sockopt_win32.c b/otherlibs/unix/sockopt_win32.c
index 64d17b08f370..06e2fd945e25 100644
--- a/otherlibs/unix/sockopt_win32.c
+++ b/otherlibs/unix/sockopt_win32.c
@@ -117,7 +117,7 @@ CAMLexport value caml_unix_getsockopt_aux(const char * name,
   CAMLparam0();
   CAMLlocal1(err);
   union option_value optval;
-  socklen_param_type optsize;
+  socklen_t optsize;
   value res;
 
   switch (ty) {
@@ -173,7 +173,7 @@ CAMLexport value caml_unix_setsockopt_aux(const char * name,
                                      value socket, value val)
 {
   union option_value optval;
-  socklen_param_type optsize;
+  socklen_t optsize;
   double f;
 
   switch (ty) {
diff --git a/runtime/caml/compatibility.h b/runtime/caml/compatibility.h
index 103170f13345..3baa978df00c 100644
--- a/runtime/caml/compatibility.h
+++ b/runtime/caml/compatibility.h
@@ -33,4 +33,8 @@
 #define HAS_UNISTD 1
 #endif
 
+#ifdef HAVE_SOCKLEN_T
+#define HAS_SOCKLEN_T 1
+#endif
+
 #endif  /* CAML_COMPATIBILITY_H */
diff --git a/runtime/caml/s.h.in b/runtime/caml/s.h.in
index ca5c510c5070..70bbc6d7a7ea 100644
--- a/runtime/caml/s.h.in
+++ b/runtime/caml/s.h.in
@@ -93,10 +93,9 @@
 /* Define HAS_SOCKETPAIR if you have the socketpair function. Only
    relevant on Windows. */
 
-#undef HAS_SOCKLEN_T
+#undef HAVE_SOCKLEN_T
 
-/* Define HAS_SOCKLEN_T if the type socklen_t is defined in
-   /usr/include/sys/socket.h. */
+/* Define HAVE_SOCKLEN_T if the type socklen_t is defined. */
 
 #undef HAS_AFUNIX_H