diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index deed8182..40ec45dd 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -77,7 +77,7 @@ jobs:
             else
               # Tag doesn't exist yet — build from HEAD
               sha="${GITHUB_SHA}"
-              source_ref="${GITHUB_REF_NAME}"
+              source_ref="${GITHUB_SHA}"
               echo "Tag ${tag} not found; building from ${source_ref} @ ${sha}"
             fi
           else
diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 08ba2f8b..2cb8f800 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -13,7 +13,8 @@ If you just want the short version, see the
 ## 1. Supported platforms
 
 CodeWhale ships matched `codewhale` and `codewhale-tui` prebuilt binaries for
-these platform/architecture combinations from v0.8.8 onward:
+these platform/architecture combinations. Linux ARM64 is available from
+v0.8.8 onward; Linux RISC-V starts with the first release after v0.8.47.
 
 | Platform     | Architecture | npm install | `cargo install` | GitHub release asset                                  |
 | ------------ | ------------ | :---------: | :-------------: | ----------------------------------------------------- |
diff --git a/npm/codewhale/test/artifacts.test.js b/npm/codewhale/test/artifacts.test.js
index 1fd74955..e16e88fd 100644
--- a/npm/codewhale/test/artifacts.test.js
+++ b/npm/codewhale/test/artifacts.test.js
@@ -55,6 +55,7 @@ test("known platforms are unaffected by alias map", () => {
   for (const [platform, arch, expectedCodeWhale] of [
     ["linux", "x64", "codewhale-linux-x64"],
     ["darwin", "arm64", "codewhale-macos-arm64"],
+    ["linux", "riscv64", "codewhale-linux-riscv64"],
     ["win32", "x64", "codewhale-windows-x64.exe"],
   ]) {
     withMockedOs(platform, arch, () => {