diff --git a/libc/kernel/uapi/linux/mmc/ioctl.h b/libc/kernel/uapi/linux/mmc/ioctl.h
index cd09b3e..3d37665 100644
--- a/libc/kernel/uapi/linux/mmc/ioctl.h
+++ b/libc/kernel/uapi/linux/mmc/ioctl.h
@@ -48,7 +48,7 @@
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define MMC_IOC_CMD _IOWR(MMC_BLOCK_MAJOR, 0, struct mmc_ioc_cmd)
 #define MMC_IOC_MULTI_CMD _IOWR(MMC_BLOCK_MAJOR, 1, struct mmc_ioc_multi_cmd)
-#define MMC_IOC_MAX_BYTES (512L * 256)
+#define MMC_IOC_MAX_BYTES (512L * 1024)
 #define MMC_IOC_MAX_CMDS 255
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif