diff --git a/data/disk2.asm b/data/disk2.asm
index 4ec649f..c210c45 100644
--- a/data/disk2.asm
+++ b/data/disk2.asm
@@ -23,7 +23,7 @@
 0A:24 3C			BIT		A1L
 0C:F0 10			BEQ		INCX
 0E:05 3C			ORA		A1L
-10:49 FF			ADC		#$FF
+10:49 FF			EOR		#$FF
 12:29 7E			AND		#$7E
 14:B0 08	HASCRY	BCS		INCX
 16:4A				LSR		A