diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index c5f210627..ea0cba811 100644
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -81,8 +81,14 @@ struct wpa_scan_result {
 };
 
 
+#define WPA_SCAN_QUAL_INVALID		BIT(0)
+#define WPA_SCAN_NOISE_INVALID		BIT(1)
+#define WPA_SCAN_LEVEL_INVALID		BIT(2)
+#define WPA_SCAN_LEVEL_DBM		BIT(3)
+
 /**
  * struct wpa_scan_res - Scan result for an BSS/IBSS
+ * @flags: information flags about the BSS/IBSS (WPA_SCAN_*)
  * @bssid: BSSID
  * @freq: frequency of the channel in MHz (e.g., 2412 = channel 1)
  * @beacon_int: beacon interval in TUs (host byte order)
@@ -103,6 +109,7 @@ struct wpa_scan_result {
  * report all IEs to make it easier to support future additions.
  */
 struct wpa_scan_res {
+	unsigned int flags;
 	u8 bssid[ETH_ALEN];
 	int freq;
 	u16 beacon_int;
diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index b75c10ef6..2f530b2e4 100644
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -1769,10 +1769,16 @@ static int bss_info_handler(struct nl_msg *msg, void *arg)
 		r->beacon_int = nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]);
 	if (bss[NL80211_BSS_CAPABILITY])
 		r->caps = nla_get_u16(bss[NL80211_BSS_CAPABILITY]);
-	if (bss[NL80211_BSS_SIGNAL_UNSPEC])
-		r->qual = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
-	if (bss[NL80211_BSS_SIGNAL_MBM])
+	r->flags |= WPA_SCAN_NOISE_INVALID;
+	if (bss[NL80211_BSS_SIGNAL_MBM]) {
 		r->level = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
+		r->level /= 100; /* mBm to dBm */
+		r->flags |= WPA_SCAN_LEVEL_DBM | WPA_SCAN_QUAL_INVALID;
+	} else if (bss[NL80211_BSS_SIGNAL_UNSPEC]) {
+		r->level = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
+		r->flags |= WPA_SCAN_LEVEL_INVALID;
+	} else
+		r->flags |= WPA_SCAN_LEVEL_INVALID | WPA_SCAN_QUAL_INVALID;
 	if (bss[NL80211_BSS_TSF])
 		r->tsf = nla_get_u64(bss[NL80211_BSS_TSF]);
 	r->ie_len = ie_len;
diff --git a/src/drivers/driver_wext.c b/src/drivers/driver_wext.c
index 1c9105b28..e6242da60 100644
--- a/src/drivers/driver_wext.c
+++ b/src/drivers/driver_wext.c
@@ -1267,6 +1267,14 @@ static void wext_get_scan_qual(struct iw_event *iwe,
 	res->res.qual = iwe->u.qual.qual;
 	res->res.noise = iwe->u.qual.noise;
 	res->res.level = iwe->u.qual.level;
+	if (iwe->u.qual.updated & IW_QUAL_QUAL_INVALID)
+		res->res.flags |= WPA_SCAN_QUAL_INVALID;
+	if (iwe->u.qual.updated & IW_QUAL_LEVEL_INVALID)
+		res->res.flags |= WPA_SCAN_LEVEL_INVALID;
+	if (iwe->u.qual.updated & IW_QUAL_NOISE_INVALID)
+		res->res.flags |= WPA_SCAN_NOISE_INVALID;
+	if (iwe->u.qual.updated & IW_QUAL_DBM)
+		res->res.flags |= WPA_SCAN_LEVEL_DBM;
 }
 
 
diff --git a/wpa_supplicant/ctrl_iface_dbus_handlers.c b/wpa_supplicant/ctrl_iface_dbus_handlers.c
index 3c298043b..161f7f887 100644
--- a/wpa_supplicant/ctrl_iface_dbus_handlers.c
+++ b/wpa_supplicant/ctrl_iface_dbus_handlers.c
@@ -436,11 +436,14 @@ DBusMessage * wpas_dbus_bssid_properties(DBusMessage *message,
 	if (!wpa_dbus_dict_append_uint16(&iter_dict, "capabilities",
 					 res->caps))
 		goto error;
-	if (!wpa_dbus_dict_append_int32(&iter_dict, "quality", res->qual))
+	if (!(res->flags & WPA_SCAN_QUAL_INVALID) &&
+	    !wpa_dbus_dict_append_int32(&iter_dict, "quality", res->qual))
 		goto error;
-	if (!wpa_dbus_dict_append_int32(&iter_dict, "noise", res->noise))
+	if (!(res->flags & WPA_SCAN_NOISE_INVALID) &&
+	    !wpa_dbus_dict_append_int32(&iter_dict, "noise", res->noise))
 		goto error;
-	if (!wpa_dbus_dict_append_int32(&iter_dict, "level", res->level))
+	if (!(res->flags & WPA_SCAN_LEVEL_INVALID) &&
+	    !wpa_dbus_dict_append_int32(&iter_dict, "level", res->level))
 		goto error;
 	if (!wpa_dbus_dict_append_int32(&iter_dict, "maxrate",
 					wpa_scan_get_max_rate(res) * 500000))