diff --git a/ocaml-srt.spec b/ocaml-srt.spec
index 2fdf74f..e628c0d 100644
--- a/ocaml-srt.spec
+++ b/ocaml-srt.spec
@@ -2,7 +2,7 @@
 
 Name:          ocaml-srt
 Version:       0.2.1
-Release:       1mamba
+Release:       2mamba
 Summary:       OCaml bindings for the Secure, Reliable, Transport protocol library 
 Group:         System/Libraries/OCaml
 Vendor:        openmamba
@@ -15,13 +15,15 @@ License:       GPL
 BuildRequires: glibc-devel
 BuildRequires: libsrt-devel
 BuildRequires: ocaml
+BuildRequires: ocaml-bigarray-compat-devel
 BuildRequires: ocaml-ctypes-devel
 BuildRequires: ocaml-integers
 BuildRequires: ocaml-posix-devel
 ## AUTOBUILDREQ-END
 BuildRequires: dune
-BuildRequires: ocaml
 BuildRequires: ocaml-findlib
+BuildRequires: ocaml-ctypes-devel >= 0.20.0-2mamba
+BuildRequires: ocaml-posix-devel >= 2.0.0-2mamba
 
 %description
 %{summary}.
@@ -71,5 +73,8 @@ rm -rf %{buildroot}/usr/doc
 %doc CHANGES* README.md
 
 %changelog
+* Wed Feb 09 2022 Silvan Calarco <silvan.calarco@mambasoft.it> 0.2.1-2mamba
+- rebuilt with ocaml-posix 2.0.0-2mamba and ocaml-ctypes 0.20.0-2mamba
+
 * Sun Feb 06 2022 Silvan Calarco <silvan.calarco@mambasoft.it> 0.2.1-1mamba
 - package created using the webbuild interface