diff --git a/pkgs/development/compilers/ocaml/4.12.nix b/pkgs/development/compilers/ocaml/4.12.nix
index 16649f09869..c422d2a15a3 100644
--- a/pkgs/development/compilers/ocaml/4.12.nix
+++ b/pkgs/development/compilers/ocaml/4.12.nix
@@ -1,9 +1,9 @@
 import ./generic.nix {
   major_version = "4";
   minor_version = "12";
-  patch_version = "0-alpha3";
+  patch_version = "0-beta1";
   src = fetchTarball {
-    url = "http://caml.inria.fr/pub/distrib/ocaml-4.12/ocaml-4.12.0~alpha3.tar.xz";
-    sha256 = "1hqlf9fi5gmvb6r13z5819rg6k813bw9ihgbbji67hhh4q361wlw";
+    url = "http://caml.inria.fr/pub/distrib/ocaml-4.12/ocaml-4.12.0~beta1.tar.xz";
+    sha256 = "1rny74mi0knl8byqg2naw1mgvn22c2zihlwvzbkd56j97flqsxsm";
   };
 }