diff --git a/ocaml/Element.mli b/ocaml/Element.mli
index 2c899b3b..e78a57ad 100644
--- a/ocaml/Element.mli
+++ b/ocaml/Element.mli
@@ -7,6 +7,7 @@ type t =
 |Na|Mg                              |Al|Si|P |S |Cl|Ar
 |K |Ca|Sc|Ti|V |Cr|Mn|Fe|Co|Ni|Cu|Zn|Ga|Ge|As|Se|Br|Kr
 |Rb|Sr|Y |Zr|Nb|Mo|Tc|Ru|Rh|Pd|Ag|Cd|In|Sn|Sb|Te|I |Xe
+                           |Pt
 with sexp
 
 (** String conversion functions *)