diff --git a/Dockerfile b/Dockerfile
index 7530285..ff2041c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -21,7 +21,7 @@
 # =============================================================================
 FROM --platform=$BUILDPLATFORM golang:1.26.3-alpine@sha256:91eda9776261207ea25fd06b5b7fed8d397dd2c0a283e77f2ab6e91bfa71079d AS builder
 
-# renovate: datasource=github-releases depName=tailscale packageName=tailscale/tailscale
+# renovate: datasource=github-releases depName=tailscale packageName=tailscale/tailscale versioning=semver
 ARG TAILSCALE_VERSION=v1.98.3
 
 # Provided automatically by buildx for the target platform.
diff --git a/renovate.json b/renovate.json
index 679d06e..4a885c4 100644
--- a/renovate.json
+++ b/renovate.json
@@ -27,9 +27,8 @@
     {
       "matchDatasources": ["github-releases"],
       "matchPackageNames": ["tailscale/tailscale"],
-      "description": "TAILSCALE_VERSION ARG: only stable releases. Tailscale uses EVEN minor versions for stable (v1.98.x); ODD minors (v1.99.x) are unstable, so filter to even minors and ignore pre-releases.",
-      "extractVersion": "^v(?<version>\\d+\\.\\d+\\.\\d+)$",
-      "allowedVersions": "/^\\d+\\.\\d*[02468]\\.\\d+$/",
+      "description": "TAILSCALE_VERSION ARG: only stable releases. Tailscale uses EVEN minor versions for stable (v1.98.x); ODD minors (v1.99.x) are unstable, so filter to even minors and ignore pre-releases. The `v` prefix is kept (no extractVersion) so the ARG value stays v-prefixed to match the git tags cloned in the Dockerfile.",
+      "allowedVersions": "/^v\\d+\\.\\d*[02468]\\.\\d+$/",
       "ignoreUnstable": true
     },
     {