diff --git a/include/zephyr/bluetooth/iso.h b/include/zephyr/bluetooth/iso.h
index 782ad7df58b6b3..4251a2c87cb1a4 100644
--- a/include/zephyr/bluetooth/iso.h
+++ b/include/zephyr/bluetooth/iso.h
@@ -140,6 +140,14 @@ extern "C" {
 /** Maximum pre-transmission offset */
 #define BT_ISO_PTO_MAX              0x0FU
 
+/**
+ * @brief Check if ISO BIS bitfield is valid (BT_ISO_BIS_INDEX_BIT(1)|..|BT_ISO_BIS_INDEX_BIT(31))
+ *
+ * @param _bis_bitfield BIS index bitfield (uint32)
+ */
+#define BT_ISO_VALID_BIS_BITFIELD(_bis_bitfield)                                                   \
+	((_bis_bitfield) != 0U && (_bis_bitfield) <= BIT_MASK(BT_ISO_BIS_INDEX_MAX))
+
 /**
  * @brief Life-span states of ISO channel. Used only by internal APIs dealing with setting channel
  * to proper state depending on operational context.
diff --git a/subsys/bluetooth/host/iso.c b/subsys/bluetooth/host/iso.c
index 17e0f3dfb20e6f..806d1a1c89c035 100644
--- a/subsys/bluetooth/host/iso.c
+++ b/subsys/bluetooth/host/iso.c
@@ -3316,7 +3316,7 @@ int bt_iso_big_sync(struct bt_le_per_adv_sync *sync, struct bt_iso_big_sync_para
 		return -EINVAL;
 	}
 
-	CHECKIF(param->bis_bitfield == 0U || param->bis_bitfield > BIT_MASK(BT_ISO_BIS_INDEX_MAX)) {
+	CHECKIF(param->bis_bitfield == 0U || !BT_ISO_VALID_BIS_BITFIELD(param->bis_bitfield)) {
 		LOG_DBG("Invalid BIS bitfield 0x%08x", param->bis_bitfield);
 		return -EINVAL;
 	}