diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 0f896c27f4..db7d04119e 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -117,7 +117,7 @@ struct SCSIDiskState {
      * 0x0000        - rotation rate not reported
      * 0x0001        - non-rotating medium (SSD)
      * 0x0002-0x0400 - reserved
-     * 0x0401-0xffe  - rotations per minute
+     * 0x0401-0xfffe - rotations per minute
      * 0xffff        - reserved
      */
     uint16_t rotation_rate;
diff --git a/include/hw/ide/ide-dev.h b/include/hw/ide/ide-dev.h
index 617e8159c7..f5eaaf68e6 100644
--- a/include/hw/ide/ide-dev.h
+++ b/include/hw/ide/ide-dev.h
@@ -160,7 +160,7 @@ struct IDEDevice {
      * 0x0000        - rotation rate not reported
      * 0x0001        - non-rotating medium (SSD)
      * 0x0002-0x0400 - reserved
-     * 0x0401-0xffe  - rotations per minute
+     * 0x0401-0xfffe - rotations per minute
      * 0xffff        - reserved
      */
     uint16_t rotation_rate;