diff --git a/.gitea/workflows/release.yml b/.gitea/workflows/release.yml
index ad2f363..b42315b 100644
--- a/.gitea/workflows/release.yml
+++ b/.gitea/workflows/release.yml
@@ -98,6 +98,13 @@ jobs:
           # a matching toolchain and never needs to download one.
           go-version-file: backend/go.mod
 
+      # The self-hosted runner keeps a persistent Go build cache. A prior run
+      # under a different (auto-downloaded) toolchain left objects that mismatch
+      # the pinned toolchain ("compile: version ... does not match go tool
+      # version"). Clear it so everything recompiles with this toolchain.
+      - name: Clean Go build cache
+        run: go clean -cache
+
       - name: Setup Node
         uses: actions/setup-node@v4
         with: