diff --git a/include/libssh/channels.h b/include/libssh/channels.h
index fc03965a..bbabcfd1 100644
--- a/include/libssh/channels.h
+++ b/include/libssh/channels.h
@@ -97,8 +97,9 @@ SSH_PACKET_CALLBACK(channel_rcv_close);
 SSH_PACKET_CALLBACK(channel_rcv_request);
 SSH_PACKET_CALLBACK(channel_rcv_data);
 
-int channel_default_bufferize(ssh_channel channel, void *data, int len,
-        int is_stderr);
+int channel_default_bufferize(ssh_channel channel,
+                              void *data, size_t len,
+                              bool is_stderr);
 int ssh_channel_flush(ssh_channel channel);
 uint32_t ssh_channel_new_id(ssh_session session);
 ssh_channel ssh_channel_from_local(ssh_session session, uint32_t id);
diff --git a/src/channels.c b/src/channels.c
index ebec0a6a..eeb94c0b 100644
--- a/src/channels.c
+++ b/src/channels.c
@@ -844,8 +844,10 @@ SSH_PACKET_CALLBACK(channel_rcv_request) {
  *
  * FIXME is the window changed?
  */
-int channel_default_bufferize(ssh_channel channel, void *data, int len,
-    int is_stderr) {
+int channel_default_bufferize(ssh_channel channel,
+                              void *data, size_t len,
+                              bool is_stderr)
+{
   ssh_session session;
 
   if(channel == NULL) {
@@ -860,8 +862,10 @@ int channel_default_bufferize(ssh_channel channel, void *data, int len,
   }
 
   SSH_LOG(SSH_LOG_PACKET,
-      "placing %d bytes into channel buffer (stderr=%d)", len, is_stderr);
-  if (is_stderr == 0) {
+          "placing %zu bytes into channel buffer (%s)",
+          len,
+          is_stderr ? "stderr" : "stdout");
+  if (!is_stderr) {
     /* stdout */
     if (channel->stdout_buffer == NULL) {
       channel->stdout_buffer = ssh_buffer_new();
diff --git a/src/connect.c b/src/connect.c
index 124b9f56..252e2c63 100644
--- a/src/connect.c
+++ b/src/connect.c
@@ -25,6 +25,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>