diff --git a/.github/workflows/opam-publish.yml b/.github/workflows/opam-publish.yml
new file mode 100644
index 00000000..593b532f
--- /dev/null
+++ b/.github/workflows/opam-publish.yml
@@ -0,0 +1,62 @@
+name: Binaryen.ml - publish to opam
+on:
+  release:
+    types: [released]
+
+jobs:
+  build:
+    name: Publish to opam
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+        ocaml-version: [4.10.0]
+
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
+
+      - name: Setup bot user
+        run: |
+          git config --global user.email "bot@grain-lang.org"
+          git config --global user.name "Grain Bot"
+
+      # Some hacks to make sure opam doesn't pull the repo in a way we can't deal with
+      - name: Setup opam repository
+        run: |
+          mkdir -p  ~/.opam/plugins/opam-publish/repos/
+          git clone git://github.com/ocaml/opam-repository ~/.opam/plugins/opam-publish/repos/ocaml%opam-repository
+          cd ~/.opam/plugins/opam-publish/repos/ocaml%opam-repository
+          git remote add user https://${{ secrets.OPAM_RELEASE }}@github.com/grain-lang/opam-repository
+
+      # Set up our token because opam doesn't support env var tokens
+      - name: Setup token
+        run: |
+          mkdir -p  ~/.opam/plugins/opam-publish/
+          echo -n ${{ secrets.OPAM_RELEASE }} > ~/.opam/plugins/opam-publish/binaryen.token
+
+      # This is the only way to make opam publish "headless" currently
+      - name: Remove xdg-open
+        run: |
+          sudo rm $(which xdg-open)
+
+      - name: Generate CHANGES file
+        run: |
+          echo -n "${{ github.event.release.body }}" > CHANGES.md
+
+      - name: Setup OCaml ${{ matrix.ocaml-version }}
+        uses: avsm/setup-ocaml@v1
+        with:
+          ocaml-version: ${{ matrix.ocaml-version }}
+
+      - name: Install local dependencies
+        run: |
+          opam install opam-publish
+
+      - name: Publish to opam
+        run: |
+          opam publish --msg-file=CHANGES.md ${{ github.event.release.assets[0].browser_download_url }}
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 68bf8193..1d66279c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -18,6 +18,8 @@ jobs:
 
       - name: Checkout code
         uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
 
       - name: Build archive
         run: |
diff --git a/binaryen.opam b/binaryen.opam
index 3537b8f8..a30c761d 100644
--- a/binaryen.opam
+++ b/binaryen.opam
@@ -1,7 +1,9 @@
 opam-version: "2.0"
+version: "0.3.0"
 synopsis: "OCaml bindings for Binaryen"
 maintainer: "oscar@grain-lang.org"
 author: "Oscar Spencer"
+license: " Apache-2.0"
 homepage: "https://github.com/grain-lang/binaryen.ml"
 dev-repo: "git+https://github.com/grain-lang/binaryen.ml.git"
 bug-reports: "https://github.com/grain-lang/binaryen.ml/issues"
diff --git a/package.json b/package.json
index e7e1df3c..3b3b5020 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "binaryen.ml",
-  "version": "0.2.2",
+  "version": "0.3.0",
   "description": "OCaml bindings for Binaryen.",
   "author": "Oscar Spencer <oscar@grain-lang.org>",
   "license": "Apache-2.0",