diff --git a/subsys/bluetooth/controller/Kconfig b/subsys/bluetooth/controller/Kconfig
index 7ef7397aa80..de86592a9cb 100644
--- a/subsys/bluetooth/controller/Kconfig
+++ b/subsys/bluetooth/controller/Kconfig
@@ -486,9 +486,16 @@ config BT_CTLR_ADV_SYNC_SET
 	help
 	  Maximum supported periodic advertising sets.
 
+config BT_CTLR_ADV_DATA_LEN_MAX
+	int "Maximum Advertising Data Length"
+	depends on BT_CTLR_ADV_EXT
+	range 31 1650
+	help
+	  Maximum Extended Advertising Data Length.
+
 config BT_CTLR_SCAN_AUX_SET
 	int "Auxiliary Channel Scan Sets"
-	depends on BT_CTLR_ADV_EXT
+	depends on BT_OBSERVER && BT_CTLR_ADV_EXT
 	range 1 64
 	help
 	  Maximum supported auxiliary channel scan sets.
diff --git a/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c b/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c
index 51ec9bd56da..1c1dcccb5c8 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c
@@ -494,8 +494,7 @@ uint8_t ll_adv_aux_sr_data_set(uint8_t handle, uint8_t op, uint8_t frag_pref, ui
 
 uint16_t ll_adv_aux_max_data_length_get(void)
 {
-	/* TODO: return a Kconfig value */
-	return 0;
+	return CONFIG_BT_CTLR_ADV_DATA_LEN_MAX;
 }
 #endif /* (CONFIG_BT_CTLR_ADV_AUX_SET > 0) */