diff --git a/src/acpi_thermal_rel_ioct.h b/src/acpi_thermal_rel_ioct.h
index dd045a9..9b12a69 100644
--- a/src/acpi_thermal_rel_ioct.h
+++ b/src/acpi_thermal_rel_ioct.h
@@ -34,17 +34,14 @@
 #define ACPI_THERMAL_GET_ART	_IOR(ACPI_THERMAL_MAGIC, 6, unsigned long)
 
 /*
- * ACPI_THERMAL_GET_PSVT_REV = Revision number
- *   identifies limit type: 1=true proportional limit, 2=depth limit
  * ACPI_THERMAL_GET_PSVT_COUNT = Number of PSVT entries
  * ACPI_THERMAL_GET_PSVT_LEN = Total return data size (PSVT count x each
  * PSVT entry size)
  * ACPI_THERMAL_GET_PSVT = Get the data as an array of psvt_objects
  */
-#define ACPI_THERMAL_GET_PSVT_REV _IOR(ACPI_THERMAL_MAGIC, 7, unsigned long)
-#define ACPI_THERMAL_GET_PSVT_LEN _IOR(ACPI_THERMAL_MAGIC, 8, unsigned long)
-#define ACPI_THERMAL_GET_PSVT_COUNT _IOR(ACPI_THERMAL_MAGIC, 9, unsigned long)
-#define ACPI_THERMAL_GET_PSVT	_IOR(ACPI_THERMAL_MAGIC, 10, unsigned long)
+#define ACPI_THERMAL_GET_PSVT_LEN _IOR(ACPI_THERMAL_MAGIC, 7, unsigned long)
+#define ACPI_THERMAL_GET_PSVT_COUNT _IOR(ACPI_THERMAL_MAGIC, 8, unsigned long)
+#define ACPI_THERMAL_GET_PSVT	_IOR(ACPI_THERMAL_MAGIC, 9, unsigned long)
 
 #ifndef __KERNEL__
 #define u64 unsigned long long