diff --git a/src/ax25.c b/src/ax25.c
index 9f5a6ce..12136aa 100644
--- a/src/ax25.c
+++ b/src/ax25.c
@@ -95,7 +95,7 @@ patty_ax25_if *patty_ax25_create_if(patty_ax25 *ax25, int opts, void *info) {
 static uint32_t address_hash(patty_ax25_address *address) {
     char key[10];
 
-    if (snprintf(key, sizeof(key), "%s/%d", callsign, ssid) < 0) {
+    if (snprintf(key, sizeof(key), "%s/%d", address->callsign, address->ssid) < 0) {
         goto error_snprintf_key;
     }