diff --git a/bigstringaf.opam b/bigstringaf.opam
index c3344d3..08e8ad8 100644
--- a/bigstringaf.opam
+++ b/bigstringaf.opam
@@ -1,3 +1,4 @@
+version: "0.9.0"
 opam-version: "2.0"
 maintainer: "Spiros Eliopoulos <spiros@inhabitedtype.com>"
 authors: [ "Spiros Eliopoulos <spiros@inhabitedtype.com>" ]