diff --git a/unison-2.40.128-ocaml-4.04.patch b/unison-2.40.128-ocaml-4.04.patch
new file mode 100644
index 0000000..50cce21
--- /dev/null
+++ b/unison-2.40.128-ocaml-4.04.patch
@@ -0,0 +1,24 @@
+diff -ur unison-2.40.128.old/fs.ml unison-2.40.128/fs.ml
+--- unison-2.40.128.old/fs.ml	2010-04-15 18:29:31.000000000 +0100
++++ unison-2.40.128/fs.ml	2017-02-14 12:52:50.260156414 +0000
+@@ -21,7 +21,7 @@
+ type dir_handle = System.dir_handle
+                 = { readdir : unit -> string; closedir : unit -> unit }
+ 
+-let symlink l f = System.symlink l (Fspath.toString f)
++let symlink ?to_dir l f = System.symlink l (Fspath.toString f)
+ 
+ let readlink f = System.readlink (Fspath.toString f)
+ 
+diff -ur unison-2.40.128.old/system/system_intf.ml unison-2.40.128/system/system_intf.ml
+--- unison-2.40.128.old/system/system_intf.ml	2010-04-15 18:29:31.000000000 +0100
++++ unison-2.40.128/system/system_intf.ml	2017-02-14 12:53:27.127978087 +0000
+@@ -20,7 +20,7 @@
+ type fspath
+ type dir_handle = { readdir : unit -> string; closedir : unit -> unit }
+ 
+-val symlink : string -> fspath -> unit
++val symlink : ?to_dir:bool -> string -> fspath -> unit
+ val readlink : fspath -> string
+ val chown : fspath -> int -> int -> unit
+ val chmod : fspath -> int -> unit
diff --git a/unison240.spec b/unison240.spec
index cfd1f78..7dfdf92 100644
--- a/unison240.spec
+++ b/unison240.spec
@@ -24,7 +24,7 @@
 
 Name:      unison%{ver_compat_name}
 Version:   %{ver_compat}%{ver_noncompat}
-Release:   6%{?dist}
+Release:   7%{?dist}
 
 Summary:   Multi-master File synchronization tool
 
@@ -35,6 +35,9 @@ Source0:   http://www.cis.upenn.edu/~bcpierce/unison/download/releases/unison-%{
 Source1:   unison.png
 Source2:   http://www.cis.upenn.edu/~bcpierce/unison/download/releases/unison-%{ver_compat}%{ver_noncompat}/unison-%{ver_compat}%{ver_noncompat}-manual.html
 
+# Minor fix for compiling against OCaml 4.04.
+Patch1:    unison-2.40.128-ocaml-4.04.patch
+
 # can't make this noarch (rpmbuild fails about unpackaged debug files)
 # BuildArch:     noarch
 ExcludeArch:   sparc64 s390 s390x
@@ -96,6 +99,8 @@ This package provides the textual version of unison without graphical interface.
 %prep
 %setup -q -n unison-%{version}
 
+%patch1 -p1
+
 cat > %{name}.desktop <<EOF
 [Desktop Entry]
 Type=Application
@@ -193,6 +198,9 @@ fi
 
 
 %changelog
+* Tue Feb 14 2017 Richard W.M. Jones <rjones@redhat.com> - 2.40.128-7
+- Small fix for compiling against OCaml 4.04 (RHBZ#1392152).
+
 * Sat Feb 11 2017 Fedora Release Engineering <releng@fedoraproject.org> - 2.40.128-6
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_26_Mass_Rebuild