diff --git a/include/apple2.enc.h b/include/apple2.enc.h
index 4e26a8b..82ccae4 100644
--- a/include/apple2.enc.h
+++ b/include/apple2.enc.h
@@ -51,7 +51,7 @@
  * the track number, the sector number, the volume, and an XOR'd
  * combination of all three.
  */
-#define ENC_ESECTOR_HEADER 0x14
+#define ENC_ESECTOR_HEADER 0x13
 
 /*
  * The track header (as mentioned for ENC_ETRACK) is 48 bytes of--well,