diff --git a/src/channels.c b/src/channels.c
index 85906d03..8e9186bd 100644
--- a/src/channels.c
+++ b/src/channels.c
@@ -533,7 +533,7 @@ SSH_PACKET_CALLBACK(channel_rcv_data){
   ssh_callbacks_iterate(channel->callbacks,
                         ssh_channel_callbacks,
                         channel_data_function) {
-      if (ssh_buffer_get(buf) == 0) {
+      if (ssh_buffer_get(buf) == NULL) {
           break;
       }
       rest = ssh_callbacks_iterate_exec(channel_data_function,