diff --git a/cmd/gbrgames/worker.go b/cmd/gbrgames/worker.go
index c8a62fd..13fbdf3 100644
--- a/cmd/gbrgames/worker.go
+++ b/cmd/gbrgames/worker.go
@@ -360,7 +360,9 @@ func (c *workerConfig) openPR(dir string, job *builderJob, res *buildResult) (st
 	if len(short) > 8 {
 		short = short[:8]
 	}
-	branch := "draft/" + res.GameID + "-" + short
+	// One branch per run: a rerun of the same job must not push onto the earlier run's branch, which
+	// may have gained review commits since
+	branch := draftBranch(res.GameID, short, time.Now())
 	auth := "http.extraHeader=Authorization: token " + c.botToken
 	steps := []struct {
 		name string
@@ -415,3 +417,7 @@ func readJSON(p string, out any) error {
 	}
 	return json.Unmarshal(raw, out)
 }
+
+func draftBranch(gameID, job string, at time.Time) string {
+	return "draft/" + gameID + "-" + job + "-" + at.UTC().Format("20060102-150405")
+}
diff --git a/cmd/gbrgames/worker_test.go b/cmd/gbrgames/worker_test.go
index 895d5fe..b81d21c 100644
--- a/cmd/gbrgames/worker_test.go
+++ b/cmd/gbrgames/worker_test.go
@@ -5,6 +5,7 @@ import (
 	"net/http/httptest"
 	"strings"
 	"testing"
+	"time"
 )
 
 func TestCheckBotNeedsPushAccess(t *testing.T) {
@@ -68,3 +69,11 @@ func TestCheckBotWithRepositoryOnlyToken(t *testing.T) {
 		t.Errorf("identity = %s <%s>", c.botLogin, c.botEmail)
 	}
 }
+
+func TestDraftBranchIsNewForEveryRun(t *testing.T) {
+	first := draftBranch("example", "4b174b2d", time.Date(2026, 10, 25, 21, 30, 0, 0, time.UTC))
+	rerun := draftBranch("example", "4b174b2d", time.Date(2026, 10, 25, 22, 5, 9, 0, time.UTC))
+	if first != "draft/example-4b174b2d-20261025-213000" || first == rerun {
+		t.Errorf("first %q, rerun %q", first, rerun)
+	}
+}