diff --git a/cmd/bd/init_team.go b/cmd/bd/init_team.go
index b5092c8e..1232611c 100644
--- a/cmd/bd/init_team.go
+++ b/cmd/bd/init_team.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/steveyegge/beads/internal/config"
 	"github.com/steveyegge/beads/internal/storage"
+	"github.com/steveyegge/beads/internal/syncbranch"
 	"github.com/steveyegge/beads/internal/ui"
 )
 
@@ -71,8 +72,8 @@ func runTeamWizard(ctx context.Context, store storage.Storage) error {
 
 		fmt.Printf("\n%s Sync branch set to: %s\n", ui.RenderPass("✓"), syncBranch)
 
-		// Set sync.branch config
-		if err := store.SetConfig(ctx, "sync.branch", syncBranch); err != nil {
+		// Set sync.branch config (GH#923: use syncbranch.Set for validation)
+		if err := syncbranch.Set(ctx, store, syncBranch); err != nil {
 			return fmt.Errorf("failed to set sync branch: %w", err)
 		}
 
diff --git a/cmd/bd/migrate.go b/cmd/bd/migrate.go
index 90f233fd..927d2c25 100644
--- a/cmd/bd/migrate.go
+++ b/cmd/bd/migrate.go
@@ -12,6 +12,7 @@ import (
 	"github.com/steveyegge/beads/internal/beads"
 	"github.com/steveyegge/beads/internal/configfile"
 	"github.com/steveyegge/beads/internal/storage/sqlite"
+	"github.com/steveyegge/beads/internal/syncbranch"
 	"github.com/steveyegge/beads/internal/types"
 	"github.com/steveyegge/beads/internal/ui"
 	"github.com/steveyegge/beads/internal/utils"
@@ -933,8 +934,8 @@ func handleToSeparateBranch(branch string, dryRun bool) {
 		return
 	}
 
-	// Update sync.branch config
-	if err := store.SetConfig(ctx, "sync.branch", b); err != nil {
+	// Update sync.branch config (GH#923: use syncbranch.Set for validation)
+	if err := syncbranch.Set(ctx, store, b); err != nil {
 		if jsonOutput {
 			outputJSON(map[string]interface{}{
 				"error":   "config_update_failed",