diff --git a/ocaml/Makefile b/ocaml/Makefile
index dc14897..5e70e2a 100644
--- a/ocaml/Makefile
+++ b/ocaml/Makefile
@@ -1,4 +1,5 @@
 VERSION?=0.2.0
+TAG?=0.3.0
 
 build:
 	dune build
@@ -12,4 +13,4 @@ prepare:
 	opam install .. --deps-only
 
 publish:
-	opam publish -v $(VERSION) -t $(VERSION) ..
+	opam publish -v $(VERSION) https://github.com/extism/extism/archive/refs/tags/v$(TAG).tar.gz ..