diff --git a/src_ext/Makefile b/src_ext/Makefile
index b075f10f4cf..4d876e1c38b 100644
--- a/src_ext/Makefile
+++ b/src_ext/Makefile
@@ -11,8 +11,8 @@ endif
 
 PATCH ?= patch
 
-URL_ocaml = https://caml.inria.fr/pub/distrib/ocaml-4.12/ocaml-4.12.0.tar.gz
-MD5_ocaml = 0863b31da0ab8ef67c5b723206f494da
+URL_ocaml = https://caml.inria.fr/pub/distrib/ocaml-4.12/ocaml-4.12.1.tar.gz
+MD5_ocaml = 4b494fe0f06af9f3ff5047fc26993e3f
 
 URL_flexdll = https://github.com/alainfrisch/flexdll/archive/0.39.tar.gz
 MD5_flexdll = c8493c7b6e95c4763b89213a9a710af5