diff --git a/subsys/bluetooth/controller/ll_sw/ull_llcp_remote.c b/subsys/bluetooth/controller/ll_sw/ull_llcp_remote.c
index 243087d0970..e6014fcd258 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_llcp_remote.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_llcp_remote.c
@@ -21,6 +21,7 @@
 #include "pdu.h"
 #include "ll.h"
 #include "ll_settings.h"
+#include "ll_feat.h"
 
 #include "lll.h"
 #include "lll/lll_df_types.h"
@@ -31,6 +32,7 @@
 #include "ull_conn_types.h"
 #include "ull_conn_internal.h"
 #include "ull_llcp.h"
+#include "ull_llcp_features.h"
 #include "ull_llcp_internal.h"
 
 #define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_HCI_DRIVER)
@@ -371,9 +373,12 @@ static void rr_tx(struct ll_conn *conn, struct proc_ctx *ctx, uint8_t opcode)
 	/* Encode LL Control PDU */
 	switch (opcode) {
 	case PDU_DATA_LLCTRL_TYPE_REJECT_IND:
-		/* TODO(thoh): Select between LL_REJECT_IND and LL_REJECT_EXT_IND */
-		llcp_pdu_encode_reject_ext_ind(pdu, conn->llcp.remote.reject_opcode,
-					       BT_HCI_ERR_LL_PROC_COLLISION);
+		if (conn->llcp.fex.valid && feature_ext_rej_ind(conn)) {
+			llcp_pdu_encode_reject_ext_ind(pdu, conn->llcp.remote.reject_opcode,
+						       BT_HCI_ERR_LL_PROC_COLLISION);
+		} else {
+			llcp_pdu_encode_reject_ind(pdu, BT_HCI_ERR_LL_PROC_COLLISION);
+		}
 		break;
 	case PDU_DATA_LLCTRL_TYPE_UNKNOWN_RSP:
 		llcp_pdu_encode_unknown_rsp(ctx, pdu);
diff --git a/tests/bluetooth/controller/ctrl_conn_update/src/main.c b/tests/bluetooth/controller/ctrl_conn_update/src/main.c
index 71ee12daa79..0aabd2e4287 100644
--- a/tests/bluetooth/controller/ctrl_conn_update/src/main.c
+++ b/tests/bluetooth/controller/ctrl_conn_update/src/main.c
@@ -918,6 +918,9 @@ void test_conn_update_central_loc_collision(void)
 	/* Role */
 	test_set_role(&conn, BT_HCI_ROLE_CENTRAL);
 
+	/* Emulate valid feature exchange */
+	conn.llcp.fex.valid = 1;
+
 	/* Connect */
 	ull_cp_state_set(&conn, ULL_CP_CONNECTED);
 
@@ -941,8 +944,6 @@ void test_conn_update_central_loc_collision(void)
 	/* Release Tx */
 	ull_cp_release_tx(&conn, tx);
 
-	/**/
-
 	/* Prepare */
 	event_prepare(&conn);
 
diff --git a/tests/bluetooth/controller/ctrl_phy_update/src/main.c b/tests/bluetooth/controller/ctrl_phy_update/src/main.c
index 6594cdd6aa5..0bfe178093b 100644
--- a/tests/bluetooth/controller/ctrl_phy_update/src/main.c
+++ b/tests/bluetooth/controller/ctrl_phy_update/src/main.c
@@ -699,6 +699,9 @@ void test_phy_update_central_loc_collision(void)
 	/* Role */
 	test_set_role(&conn, BT_HCI_ROLE_CENTRAL);
 
+	/* Emulate valid feature exchange */
+	conn.llcp.fex.valid = 1;
+
 	/* Connect */
 	ull_cp_state_set(&conn, ULL_CP_CONNECTED);
 
diff --git a/tests/bluetooth/controller/mock_ctrl/include/kconfig.h b/tests/bluetooth/controller/mock_ctrl/include/kconfig.h
index d1c80e9126c..a5a097ea2b8 100644
--- a/tests/bluetooth/controller/mock_ctrl/include/kconfig.h
+++ b/tests/bluetooth/controller/mock_ctrl/include/kconfig.h
@@ -75,6 +75,10 @@
 #define CONFIG_BT_CTLR_CONN_PARAM_REQ y
 #endif
 
+#ifndef CONFIG_BT_CTLR_EXT_REJ_IND
+#define CONFIG_BT_CTLR_EXT_REJ_IND y
+#endif
+
 #ifndef CONFIG_BT_CTLR_XTAL_ADVANCED
 #define CONFIG_BT_CTLR_XTAL_ADVANCED y
 #endif