diff --git a/src/processor/memory/rom/mbcs.rs b/src/processor/memory/rom/mbcs.rs
index 1b5bfea..326fdf2 100644
--- a/src/processor/memory/rom/mbcs.rs
+++ b/src/processor/memory/rom/mbcs.rs
@@ -105,6 +105,7 @@ impl MBC for MBC1 {
             }
             _ => {}
         }
+        self.rom_bank = (self.rom_bank as usize % self.num_banks) as u8;
         return;
     }
 }