1 files changed, 1 insertions, 1 deletions

diff --git a/NesFile.cs b/NesFile.cs
index 4c2fcb4..ddcb076 100644
--- a/NesFile.cs
+++ b/NesFile.cs
@@ -787,7 +787,7 @@ namespace com.clusterrr.Famicom.Containers
                 if (length8k <= 0xEFF)

                 {

                     header[5] = (byte)(length8k & 0xFF);

-                    header[9] = (byte)((length8k >> 4) & 0xF0);

+                    header[9] |= (byte)((length8k >> 4) & 0xF0);

                 }

                 else

                 {