diff --git a/src/bluetooth.h b/src/bluetooth.h
index d40f71b05..6e135bf06 100644
--- a/src/bluetooth.h
+++ b/src/bluetooth.h
@@ -121,12 +121,6 @@ typedef enum {
 #define HCI_SCO_DATA_PACKET     0x03
 #define HCI_EVENT_PACKET        0x04
 
-// packet header sizes
-#define HCI_CMD_HEADER_SIZE          3
-#define HCI_ACL_HEADER_SIZE          4
-#define HCI_SCO_HEADER_SIZE          3
-#define HCI_EVENT_HEADER_SIZE        2
-
 /** 
  * HCI Layer
  */
@@ -324,9 +318,6 @@ typedef enum {
 #define HCI_ACL_2DH5_SIZE          679
 #define HCI_ACL_3DH5_SIZE         1021
        
-#define HCI_EVENT_PAYLOAD_SIZE     255
-#define HCI_CMD_PAYLOAD_SIZE       255
-
 #define LE_ADVERTISING_DATA_SIZE    31
 
 // Link Policy Settings
diff --git a/src/hci.h b/src/hci.h
index c1ca50cc6..953f3fa8c 100644
--- a/src/hci.h
+++ b/src/hci.h
@@ -141,6 +141,15 @@ extern "C" {
 #endif
 #endif
 
+// packet header sizes
+#define HCI_CMD_HEADER_SIZE          3
+#define HCI_ACL_HEADER_SIZE          4
+#define HCI_SCO_HEADER_SIZE          3
+#define HCI_EVENT_HEADER_SIZE        2
+
+#define HCI_EVENT_PAYLOAD_SIZE     255
+#define HCI_CMD_PAYLOAD_SIZE       255
+
 // 
 #define IS_COMMAND(packet, command) (little_endian_read_16(packet,0) == command.opcode)
 
diff --git a/src/hci_transport.h b/src/hci_transport.h
index 7d2676486..2a6e93b85 100644
--- a/src/hci_transport.h
+++ b/src/hci_transport.h
@@ -55,6 +55,14 @@
 extern "C" {
 #endif
 
+/**
+ * packet types - used in BTstack and over the H4 UART interface
+ */
+#define HCI_COMMAND_DATA_PACKET 0x01
+#define HCI_ACL_DATA_PACKET     0x02
+#define HCI_SCO_DATA_PACKET     0x03
+#define HCI_EVENT_PACKET        0x04
+    
 /* API_START */
 
 /* HCI packet types */