diff --git a/internal/run/upgrade.go b/internal/run/upgrade.go
index 80d8084..1a17814 100644
--- a/internal/run/upgrade.go
+++ b/internal/run/upgrade.go
@@ -47,6 +47,7 @@ func NewUpgrade(cfg env.Config) *Upgrade {
 		reuseValues:     cfg.ReuseValues,
 		timeout:         cfg.Timeout,
 		force:           cfg.Force,
+		forceConflict:   cfg.ForceConflicts, // FIXED: Added missing struct mapping
 		atomic:          cfg.AtomicUpgrade,
 		cleanupOnFail:   cfg.CleanupOnFail,
 		historyMax:      cfg.HistoryMax,
@@ -70,6 +71,11 @@ func (u *Upgrade) Prepare() error {
 		return fmt.Errorf("release is required")
 	}
 
+	// Validation: prevent generating invalid flags together
+	if u.force && u.forceConflict {
+		return fmt.Errorf("cannot use both 'force' (--force-replace) and 'force_conflicts' (--force-conflicts) together")
+	}
+
 	args := u.globalFlags()
 	args = append(args, "upgrade", "--install")