diff --git a/chain/vm/fvm.go b/chain/vm/fvm.go
index ff0858dcf20..bb2485694d0 100644
--- a/chain/vm/fvm.go
+++ b/chain/vm/fvm.go
@@ -411,7 +411,7 @@ func NewDebugFVM(ctx context.Context, opts *VMOpts) (*FVM, error) {
 			for _, e := range mf.Entries {
 				from, ok := fromMap[e.Name]
 				if !ok {
-					return nil, xerrors.Errorf("error mapping %d for debug redirect: %w", e.Name, err)
+					return nil, xerrors.Errorf("error mapping %s for debug redirect: %w", e.Name, err)
 				}
 				actorRedirect[from] = e.Code
 			}