diff --git a/lwt-safe-strings.patch b/lwt-safe-strings.patch
new file mode 100644
index 0000000..8eddb50
--- /dev/null
+++ b/lwt-safe-strings.patch
@@ -0,0 +1,14 @@
+diff -ur lwt-2.5.0.old/src/ssl/lwt_ssl.mli lwt-2.5.0/src/ssl/lwt_ssl.mli
+--- lwt-2.5.0.old/src/ssl/lwt_ssl.mli	2015-07-03 13:39:30.000000000 +0100
++++ lwt-2.5.0/src/ssl/lwt_ssl.mli	2017-11-17 16:07:20.829197330 +0000
+@@ -56,8 +56,8 @@
+ val ssl_accept_handshake  : uninitialized_socket -> socket Lwt.t
+ (** Await a SSL/TLS handshake on the specified socket (used by servers). *)
+ 
+-val read : socket -> string -> int -> int -> int Lwt.t
+-val write : socket -> string -> int -> int -> int Lwt.t
++val read : socket -> bytes -> int -> int -> int Lwt.t
++val write : socket -> bytes -> int -> int -> int Lwt.t
+ 
+ val read_bytes : socket -> Lwt_bytes.t -> int -> int -> int Lwt.t
+ val write_bytes : socket -> Lwt_bytes.t -> int -> int -> int Lwt.t
diff --git a/ocaml-lwt.spec b/ocaml-lwt.spec
index 788ba12..5d6fd59 100644
--- a/ocaml-lwt.spec
+++ b/ocaml-lwt.spec
@@ -21,6 +21,9 @@ Source0:        https://github.com/ocsigen/lwt/archive/2.5.0/lwt-2.5.0.tar.gz
 # Change some deprecated functions for OCaml 4.5.0.
 Patch1:         lwt-2.5.0-ocaml45.patch
 
+# Safe strings for OCaml 4.06.
+Patch2:         lwt-safe-strings.patch
+
 BuildRequires:  ocaml >= 3.10.0
 BuildRequires:  ocaml-ocamlbuild
 BuildRequires:  ocaml-findlib-devel
@@ -50,8 +53,7 @@ developing applications that use %{name}.
 
 %prep
 %setup -q -n lwt-%{version}
-
-%patch1 -p1
+%autopatch -p1
 
 
 %build