diff --git a/src/ax25.c b/src/ax25.c
index 162843b..1a54082 100644
--- a/src/ax25.c
+++ b/src/ax25.c
@@ -13,8 +13,7 @@ enum addr_state {
 
 int patty_ax25_pton(const char *callsign,
                     patty_ax25_addr *addr) {
-    size_t len = strlen(callsign),
-           max = PATTY_AX25_CALLSIGN_LEN + 3; /* Account for SSID suffixes */
+    size_t len = strlen(callsign);
 
     int i,
         o      = 0,
@@ -26,8 +25,8 @@ int patty_ax25_pton(const char *callsign,
 
     if (len == 0) {
         goto error_invalid_callsign;
-    } else if (len > max) {
-        len = max;
+    } else if (len > PATTY_AX25_ADDRSTRLEN) {
+        len = PATTY_AX25_ADDRSTRLEN;
     }
 
     for (i=0; i<len; i++) {