diff --git a/src/csn1.h b/src/csn1.h
index 7eef5c8..761293d 100644
--- a/src/csn1.h
+++ b/src/csn1.h
@@ -493,9 +493,11 @@
  * The value of the address is called a selector. Up to 256 (UCHAR_MAX) unique
  * selectors can be handled, longer choice list would cause CSN_ERROR_IN_SCRIPT.
  * After unpacking, this value is then converted to the sequential number of the
- * element in the union and stored in the UnionType variable.
+ * element in the union and stored in the UnionType variable (Par2).
  *      Par1: C structure name
- *      Par2: C structure element name
+ *      Par2: C structure field name holding sequential number of the chosen element.
+ *            BEWARE! Never use an enumerated type here, because its length is
+ *            compiler/machine dependent, while decoder would cast it to guint8.
  *      Par3: address of an array of type CSN_ChoiceElement_t where all possible
  *            values of the selector are provided, together with the selector
  *            length expressed in bits and the address of  the CSN_DESCR type
diff --git a/src/gsm_rlcmac.h b/src/gsm_rlcmac.h
index e9ae20a..9d859f3 100644
--- a/src/gsm_rlcmac.h
+++ b/src/gsm_rlcmac.h
@@ -158,7 +158,7 @@
 {
   guint8 PEAK_THROUGHPUT_CLASS;
   guint8 RADIO_PRIORITY;
-  RLC_MODE_t RLC_MODE;
+  guint8 RLC_MODE;
   guint8 LLC_PDU_TYPE;
   guint16 RLC_OCTET_COUNT;
 } Channel_Request_Description_t;
@@ -1245,7 +1245,7 @@
 
 typedef struct
 {
-  AccessTechnology_t Access_Technology_Type;
+  guint8              Access_Technology_Type;
   guint8              GMSK_Power_class;
   guint8              Eight_PSK_Power_class;
 } Additional_access_technologies_struct_t;