diff --git a/os/net/mac/framer/framer-802154.c b/os/net/mac/framer/framer-802154.c
index 7122c5ccd..b4c24da19 100644
--- a/os/net/mac/framer/framer-802154.c
+++ b/os/net/mac/framer/framer-802154.c
@@ -171,7 +171,6 @@ framer_802154_setup_params(packetbuf_attr_t (*get_attr)(uint8_t type),
 #if LLSEC802154_USES_EXPLICIT_KEYS
   params->aux_hdr.security_control.key_id_mode = get_attr(PACKETBUF_ATTR_KEY_ID_MODE);
   params->aux_hdr.key_index = get_attr(PACKETBUF_ATTR_KEY_INDEX);
-  params->aux_hdr.key_source.u16[0] = get_attr(PACKETBUF_ATTR_KEY_SOURCE_BYTES_0_1);
 #endif /* LLSEC802154_USES_EXPLICIT_KEYS */
 #else
   params->fcf.security_enabled = 0;
@@ -273,7 +272,6 @@ parse(void)
 #if LLSEC802154_USES_EXPLICIT_KEYS
       packetbuf_set_attr(PACKETBUF_ATTR_KEY_ID_MODE, frame.aux_hdr.security_control.key_id_mode);
       packetbuf_set_attr(PACKETBUF_ATTR_KEY_INDEX, frame.aux_hdr.key_index);
-      packetbuf_set_attr(PACKETBUF_ATTR_KEY_SOURCE_BYTES_0_1, frame.aux_hdr.key_source.u16[0]);
 #endif /* LLSEC802154_USES_EXPLICIT_KEYS */
     }
 #endif /* LLSEC802154_USES_AUX_HEADER */
diff --git a/os/net/packetbuf.h b/os/net/packetbuf.h
index 39ce4a467..20e071474 100644
--- a/os/net/packetbuf.h
+++ b/os/net/packetbuf.h
@@ -236,7 +236,6 @@ enum {
 #if LLSEC802154_USES_EXPLICIT_KEYS
   PACKETBUF_ATTR_KEY_ID_MODE,
   PACKETBUF_ATTR_KEY_INDEX,
-  PACKETBUF_ATTR_KEY_SOURCE_BYTES_0_1,
 #endif /* LLSEC802154_USES_EXPLICIT_KEYS */
 
   /* Scope 2 attributes: used between end-to-end nodes. */