diff --git a/zarrviewer b/zarrviewer
index 2969f78..2bbedd0 100755
--- a/zarrviewer
+++ b/zarrviewer
@@ -221,7 +221,7 @@ def main():
                 if time_dim is None:
                     nombre_imagen = f"mapa_{var_name}.png"
                 else:
-                    nombre_imagen = f"mapa_{var_name}_frame{frame_idx}_{pd.to_datetime(times[frame_idx]).strftime('%Y%m%d_%H%M')}.png"
+                    nombre_imagen = f"mapa_{var_name}_frame{frame_idx:03d}_{pd.to_datetime(times[frame_idx]).strftime('%Y%m%d_%H%M')}.png"
 
             # CASO B: Puntos / Estaciones (1D adicional)
             elif len(other_dims) == 1: