diff --git a/Makefile.in b/Makefile.in
index 5160889..6c25d58 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -37,7 +37,7 @@ EXE = @EXE@
 LIBEXT = @LIBEXT@
 OBJEXT = @OBJEXT@
 
-INCLUDES =
+INCLUDES =  @OCAMLINCLUDE@
 BFLAGS = -dtypes -g $(INCLUDES)
 OFLAGS = -dtypes $(INCLUDES) -for-pack Functory
 
diff --git a/configure.in b/configure.in
index bd8921d..ad9faf2 100644
--- a/configure.in
+++ b/configure.in
@@ -67,6 +67,8 @@ echo "ocaml library path is $OCAMLLIB"
 case $OCAMLVERSION in
   0.*|1.*|2.*|3.*|4.00*|4.01*)
         AC_MSG_ERROR(You need OCaml 4.02 or higher);;
+  5.*)
+	OCAMLINCLUDE="-I +unix";;
 esac
 
 
@@ -173,6 +175,7 @@ AC_SUBST(OCAMLVERSION)
 AC_SUBST(OCAMLLIB)
 AC_SUBST(OCAMLWEB)
 AC_SUBST(OCAMLWIN32)
+AC_SUBST(OCAMLINCLUDE)
 AC_SUBST(EXE)
 AC_SUBST(LIBEXT)
 AC_SUBST(OBJEXT)
diff --git a/network.ml b/network.ml
index b1a7aed..e0f8d60 100644
--- a/network.ml
+++ b/network.ml
@@ -375,7 +375,7 @@ end = struct
   module S =
     Set.Make(struct
 	       type t = worker
-	       let compare w1 w2 = Pervasives.compare w1.worker_id w2.worker_id
+	       let compare w1 w2 = Stdlib.compare w1.worker_id w2.worker_id
 	     end)
   type t = S.t ref
   let create () = ref S.empty