diff --git a/fw/wmi_unified.h b/fw/wmi_unified.h
index b57421c0a96c..f7e35eec3cfd 100644
--- a/fw/wmi_unified.h
+++ b/fw/wmi_unified.h
@@ -6523,6 +6523,15 @@ typedef struct {
 #define WMI_SGI_HE_1600_NS     0x8 /* for HE 1600 nsec */
 #define WMI_SGI_HE_3200_NS    0x10 /* for HE 3200 nsec */
 
+/*
+ * Param values to be sent for WMI_VDEV_PARAM_HE_LTF command
+ * which are used in 11ax systems
+ */
+#define WMI_HE_LTF_DEFAULT 0x0
+#define WMI_HE_LTF_1X      0x1
+#define WMI_HE_LTF_2X      0x2
+#define WMI_HE_LTF_4X      0x3
+
 /** values for vdev_subtype */
 #define WMI_UNIFIED_VDEV_SUBTYPE_P2P_DEVICE 0x1
 #define WMI_UNIFIED_VDEV_SUBTYPE_P2P_CLIENT 0x2
@@ -7712,6 +7721,14 @@ typedef enum {
      */
     WMI_VDEV_PARAM_REPEAT_PROBE_TIME, /* units = milliseconds */
 
+    /** specify the HE LTF setting that should be used for fixed rate
+     * transmissions.
+     *
+     * Expects values of WMI_HE_LTF_DEFAULT, WMI_HE_LTF_1X, WMI_HE_LTF_2X,
+     * or WMI_HE_LTF_4X.
+     */
+    WMI_VDEV_PARAM_HE_LTF,
+
 
     /*=== ADD NEW VDEV PARAM TYPES ABOVE THIS LINE ===
      * The below vdev param types are used for prototyping, and are
diff --git a/fw/wmi_version.h b/fw/wmi_version.h
index 7684d3ffc0bb..061f167628dd 100644
--- a/fw/wmi_version.h
+++ b/fw/wmi_version.h
@@ -36,7 +36,7 @@
 #define __WMI_VER_MINOR_    0
 /** WMI revision number has to be incremented when there is a
  *  change that may or may not break compatibility. */
-#define __WMI_REVISION_ 438
+#define __WMI_REVISION_ 439
 
 /** The Version Namespace should not be normally changed. Only
  *  host and firmware of the same WMI namespace will work