diff --git a/subsys/bluetooth/controller/ll_sw/ull.c b/subsys/bluetooth/controller/ll_sw/ull.c
index faa272ae5d6..e013563fd18 100644
--- a/subsys/bluetooth/controller/ll_sw/ull.c
+++ b/subsys/bluetooth/controller/ll_sw/ull.c
@@ -166,19 +166,30 @@ static MFIFO_DEFINE(pdu_rx_free, sizeof(void *), PDU_RX_CNT);
 		      PDU_RX_USER_PDU_OCTETS_MAX)              \
 	)
 
-#define PDU_RX_POOL_SIZE (PDU_RX_NODE_POOL_ELEMENT_SIZE * (RX_CNT + 1))
+/* When both central and peripheral are supported, one each Rx node will be
+ * needed by connectable advertising and the initiator to generate connection
+ * complete event, hence conditionally set the count.
+ */
+#if defined(CONFIG_BT_MAX_CONN)
+#if defined(CONFIG_BT_CENTRAL) && defined(CONFIG_BT_PERIPHERAL)
+#define BT_CTLR_MAX_CONNECTABLE 2
+#else
+#define BT_CTLR_MAX_CONNECTABLE 1
+#endif
+#define BT_CTLR_MAX_CONN        CONFIG_BT_MAX_CONN
+#else
+#define BT_CTLR_MAX_CONNECTABLE 0
+#define BT_CTLR_MAX_CONN        0
+#endif
+
+#define PDU_RX_POOL_SIZE (PDU_RX_NODE_POOL_ELEMENT_SIZE * \
+			  (RX_CNT + BT_CTLR_MAX_CONNECTABLE))
 
 static struct {
 	void *free;
 	u8_t pool[PDU_RX_POOL_SIZE];
 } mem_pdu_rx;
 
-#if defined(CONFIG_BT_MAX_CONN)
-#define BT_CTLR_MAX_CONN CONFIG_BT_MAX_CONN
-#else
-#define BT_CTLR_MAX_CONN 0
-#endif
-
 #define LINK_RX_POOL_SIZE (sizeof(memq_link_t) * (RX_CNT + 2 + \
 						  BT_CTLR_MAX_CONN))
 static struct {