diff --git a/include/patty/ax25/frame.h b/include/patty/ax25/frame.h
index bd62e4a..b9eac05 100644
--- a/include/patty/ax25/frame.h
+++ b/include/patty/ax25/frame.h
@@ -19,11 +19,6 @@ enum patty_ax25_frame_cr {
     PATTY_AX25_FRAME_RESPONSE
 };
 
-enum patty_ax25_frame_format {
-    PATTY_AX25_FRAME_NORMAL   = 0,
-    PATTY_AX25_FRAME_EXTENDED = 1
-};
-
 typedef struct _patty_ax25_frame {
     patty_ax25_address dest;
     patty_ax25_address src;
@@ -45,7 +40,6 @@ typedef struct _patty_ax25_frame {
     size_t size;
 } patty_ax25_frame;
 
-int patty_ax25_frame_decode(patty_ax25_frame *frame,
-    void *data, size_t len, enum patty_ax25_frame_format format);
+int patty_ax25_frame_decode(patty_ax25_frame *frame, void *data, size_t len);
 
 #endif /* _PATTY_AX25_FRAME_H */
diff --git a/src/decode.c b/src/decode.c
index 0bef839..f6ac1f4 100644
--- a/src/decode.c
+++ b/src/decode.c
@@ -107,7 +107,7 @@ int main(int argc, char **argv) {
     while ((len = patty_kiss_tnc_recv(tnc, &data, &port)) > 0) {
         patty_ax25_frame frame;
 
-        if (patty_ax25_frame_decode(&frame, data, len, PATTY_AX25_FRAME_NORMAL) < 0) {
+        if (patty_ax25_frame_decode(&frame, data, len) < 0) {
             perror("Unable to decode frame");
 
             exit(127);
@@ -121,10 +121,7 @@ int main(int argc, char **argv) {
             fprintf(stderr, " nr %d",   PATTY_AX25_CONTROL_SEQ_RECV(frame.control));
         }
 
-        if (frame.payload) {
-            fprintf(stderr, " proto %02x", frame.proto);
-        }
-
+        fprintf(stderr, " proto %02x", frame.proto);
         fprintf(stderr, " %ld bytes\n", len);
 
         hexdump_fprint(stderr, data, len);
diff --git a/src/frame.c b/src/frame.c
index 9d5b61e..ad149a1 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -3,7 +3,7 @@
 
 #include <patty/ax25.h>
 
-static ssize_t frame_decode_station(patty_ax25_address *address, void *data, off_t offset, enum patty_ax25_frame_format format) {
+static ssize_t frame_decode_station(patty_ax25_address *address, void *data, off_t offset) {
     int i, space = 0;
     uint8_t ssid = ((uint8_t *)data + offset)[6];
 
@@ -59,7 +59,7 @@ error:
     return -1;
 }
 
-static ssize_t frame_decode_hops(patty_ax25_frame *frame, void *data, off_t start, enum patty_ax25_frame_format format) {
+static ssize_t frame_decode_hops(patty_ax25_frame *frame, void *data, off_t start) {
     ssize_t decoded;
       off_t offset = start;
 
@@ -70,7 +70,7 @@ static ssize_t frame_decode_hops(patty_ax25_frame *frame, void *data, off_t star
      * frame.
      */
     for (i=0; i<PATTY_AX25_MAX_HOPS; i++) {
-        if ((decoded = frame_decode_station(&frame->repeaters[i], data, offset, format)) < 0) {
+        if ((decoded = frame_decode_station(&frame->repeaters[i], data, offset)) < 0) {
             goto error;
         } else {
             offset += decoded;
@@ -101,11 +101,11 @@ error:
     return -1;
 }
 
-static ssize_t frame_decode_address(patty_ax25_frame *frame, void *data, off_t start, enum patty_ax25_frame_format format) {
+static ssize_t frame_decode_address(patty_ax25_frame *frame, void *data, off_t start) {
       off_t offset = start;
     ssize_t decoded;
 
-    if ((decoded = frame_decode_station(&frame->dest, data, offset, format)) < 0) {
+    if ((decoded = frame_decode_station(&frame->dest, data, offset)) < 0) {
         goto error;
     } else {
         offset += decoded;
@@ -115,7 +115,7 @@ static ssize_t frame_decode_address(patty_ax25_frame *frame, void *data, off_t s
      * It would be considered erroneous if the destination address did have the
      * extension bit set to 1.
      */
-    if ((decoded = frame_decode_station(&frame->src, data, offset, format)) < 0) {
+    if ((decoded = frame_decode_station(&frame->src, data, offset)) < 0) {
         goto error;
     } else {
         offset += decoded;
@@ -140,7 +140,7 @@ static ssize_t frame_decode_address(patty_ax25_frame *frame, void *data, off_t s
      * decoding repeater addresses.
      */
     if (!frame->src.last) {
-        if ((decoded = frame_decode_hops(frame, data, offset, format)) < 0) {
+        if ((decoded = frame_decode_hops(frame, data, offset)) < 0) {
             goto error;
         } else {
             offset += decoded;
@@ -153,7 +153,7 @@ error:
     return -1;
 }
 
-static ssize_t frame_decode_payload(patty_ax25_frame *frame, void *data, off_t offset, enum patty_ax25_frame_format format) {
+static ssize_t frame_decode_payload(patty_ax25_frame *frame, void *data, off_t offset) {
     uint8_t control = ((uint8_t *)data + offset)[0];
      size_t decoded = 0;
 
@@ -204,7 +204,7 @@ error:
     return -1;
 }
 
-int patty_ax25_frame_decode(patty_ax25_frame *frame, void *data, size_t size, enum patty_ax25_frame_format format) {
+int patty_ax25_frame_decode(patty_ax25_frame *frame, void *data, size_t size) {
     ssize_t decoded;
       off_t offset = 0;
 
@@ -215,7 +215,7 @@ int patty_ax25_frame_decode(patty_ax25_frame *frame, void *data, size_t size, en
     /*
      * First, decode the variable-length Address field.
      */
-    if ((decoded = frame_decode_address(frame, data, offset, format)) < 0) {
+    if ((decoded = frame_decode_address(frame, data, offset)) < 0) {
         goto error_decode;
     } else {
         offset += decoded;
@@ -225,7 +225,7 @@ int patty_ax25_frame_decode(patty_ax25_frame *frame, void *data, size_t size, en
      * Now, decode the remaining Control Field, optional Protocol Identifier
      * field, and payload that may follow.
      */
-    if ((decoded = frame_decode_payload(frame, data, offset, format)) < 0) {
+    if ((decoded = frame_decode_payload(frame, data, offset)) < 0) {
         goto error_decode;
     } else {
         offset += decoded;