--- nono/host/diskimage.cpp	2026/04/29 17:05:00	1.1.1.2
+++ nono/host/diskimage.cpp	2026/04/29 17:05:11	1.1.1.3
@@ -132,7 +132,7 @@ DiskImage::Read(void *buf, off_t offset,
 {
 	assert((bool)driver);
 
-	if (__predict_false(offset + size >= GetSize())) {
+	if (__predict_false(offset + size > GetSize())) {
 		return false;
 	}
 
@@ -178,7 +178,7 @@ DiskImage::Write(const void *buf, off_t
 {
 	assert((bool)driver);
 
-	if (__predict_false(offset + size >= GetSize())) {
+	if (__predict_false(offset + size > GetSize())) {
 		return false;
 	}