diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 2f785eb..512380c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -188,7 +188,10 @@ jobs:
     needs: [prepare, publish]
     runs-on: ubuntu-latest
     steps:
+      # The tag, not main, so the template and the licence are the ones this release shipped.
       - uses: actions/checkout@v7
+        with:
+          ref: ${{ needs.prepare.outputs.tag }}
 
       - name: Render the PKGBUILD for this release
         env:
@@ -199,8 +202,13 @@ jobs:
           # From the published asset, so the checksum is of the artifact users will actually fetch.
           curl -fsSL --retry 3 -o package.deb "$URL"
           SHA=$(sha256sum package.deb | cut -d' ' -f1)
-          sed -e "s/@VERSION@/$VERSION/g" -e "s/@SHA256@/$SHA/g" packaging/aur/PKGBUILD.in > PKGBUILD
-          echo "pkgver $VERSION, sha256 $SHA"
+          # The PKGBUILD fetches the licence from the tag, so checksum the copy at that same tag.
+          LICENSE_SHA=$(sha256sum LICENSE | cut -d' ' -f1)
+          sed -e "s/@VERSION@/$VERSION/g" \
+              -e "s/@SHA256@/$SHA/g" \
+              -e "s/@LICENSE_SHA256@/$LICENSE_SHA/g" \
+              packaging/aur/PKGBUILD.in > PKGBUILD
+          echo "pkgver $VERSION, deb $SHA, licence $LICENSE_SHA"
 
       - name: Generate .SRCINFO
         # makepkg is Arch-only and refuses to run as root, hence the container and the throwaway
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..80d92ee
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Priyanshu Jain
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/package.json b/package.json
index aa1bd38..5365f6a 100644
--- a/package.json
+++ b/package.json
@@ -2,6 +2,7 @@
   "name": "margin-calendar",
   "private": true,
   "version": "0.0.1",
+  "license": "MIT",
   "type": "module",
   "scripts": {
     "dev": "vite",
diff --git a/packaging/aur/PKGBUILD.in b/packaging/aur/PKGBUILD.in
index 12de25a..f7ea777 100644
--- a/packaging/aur/PKGBUILD.in
+++ b/packaging/aur/PKGBUILD.in
@@ -13,15 +13,17 @@ pkgrel=1
 pkgdesc="A calendar for Google Calendar, where the grid owns the window and the day fits without scrolling"
 arch=('x86_64')
 url="https://github.com/priyanshujain/margin-calendar"
-license=('custom')
+license=('MIT')
 depends=('webkit2gtk-4.1' 'gtk3')
 provides=('margin-calendar')
 conflicts=('margin-calendar')
 # Prebuilt and already linked: stripping it again buys nothing and risks the binary.
 options=('!strip' '!debug')
-source=("${pkgname}-${pkgver}.deb::${url}/releases/download/v${pkgver}/Margin.Calendar_${pkgver}_amd64.deb")
+source=("${pkgname}-${pkgver}.deb::${url}/releases/download/v${pkgver}/Margin.Calendar_${pkgver}_amd64.deb"
+        "LICENSE-${pkgver}::https://raw.githubusercontent.com/priyanshujain/margin-calendar/v${pkgver}/LICENSE")
 noextract=("${pkgname}-${pkgver}.deb")
-sha256sums=('@SHA256@')
+sha256sums=('@SHA256@'
+            '@LICENSE_SHA256@')
 
 package() {
     bsdtar -xOf "${pkgname}-${pkgver}.deb" data.tar.gz | bsdtar -xf - -C "${pkgdir}"
@@ -29,4 +31,7 @@ package() {
     # copes with that, and nothing that reads it enjoys it.
     mv "${pkgdir}/usr/share/applications/Margin Calendar.desktop" \
        "${pkgdir}/usr/share/applications/margin-calendar.desktop"
+    # MIT is not one of the licences Arch keeps in /usr/share/licenses/common, so every package
+    # under it has to carry its own copy.
+    install -Dm644 "LICENSE-${pkgver}" "${pkgdir}/usr/share/licenses/${pkgname}/LICENSE"
 }
diff --git a/src-tauri/Cargo.toml b/src-tauri/Cargo.toml
index 8f6f8c6..efdb30c 100644
--- a/src-tauri/Cargo.toml
+++ b/src-tauri/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.0.1"
 description = "A calendar for Google Calendar"
 authors = ["Margin"]
 edition = "2021"
+license = "MIT"
 
 [lib]
 name = "margin_calendar_lib"