diff --git a/.github/workflows/propose-program-upgrade.yml b/.github/workflows/propose-program-upgrade.yml
index 1cad5658..8a0dea7a 100644
--- a/.github/workflows/propose-program-upgrade.yml
+++ b/.github/workflows/propose-program-upgrade.yml
@@ -15,6 +15,9 @@ on:
         type: choice
         options: [devnet, mainnet]
         default: devnet
+      ref:
+        description: Commit SHA, release tag, or branch of the program to propose. Defaults to the ref the workflow runs on.
+        default: ""
       proposal_name:
         description: Squads proposal memo
         default: Upgrade delegation program
@@ -36,6 +39,7 @@ jobs:
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
+          ref: ${{ inputs.ref }}
           persist-credentials: false
 
       - uses: magicblock-labs/.github/actions/squads-program-upgrade@2789218e3d6332e244eb2aa55b87cfb9c10c5a7f
diff --git a/README.md b/README.md
index 932e2ae7..127499e9 100644
--- a/README.md
+++ b/README.md
@@ -58,7 +58,8 @@ CI only proposes them.
    with `dry_run`). It builds `delegation_program` verifiably, uploads a buffer,
    and opens a Squads proposal that upgrades the program and records its
    verified build. The job summary shows the proposal number and executable
-   hash.
+   hash. Set `ref` to a commit SHA, release tag or branch to build that
+   source instead of the one the workflow is run from.
 2. Members review and approve the proposal in the Squads app for mainnet. For
    devnet, members can use the shared command-line tools with their own keypair.
 3. Once approved, any member with Execute permission executes it.