diff --git a/src/sock.c b/src/sock.c
index 1c87d60..cf77235 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -198,9 +198,18 @@ void patty_ax25_sock_destroy(patty_ax25_sock *sock) {
         (void)close(sock->fd);
     }
 
-    free(sock->tx_slots);
-    free(sock->rx_buf);
-    free(sock->tx_buf);
+    if (sock->tx_slots) {
+        free(sock->tx_slots);
+    }
+
+    if (sock->rx_buf) {
+        free(sock->rx_buf);
+    }
+
+    if (sock->tx_buf) {
+        free(sock->tx_buf);
+    }
+
     free(sock);
 }