diff --git a/src/channels.c b/src/channels.c
index 6b7abb61..871e1401 100644
--- a/src/channels.c
+++ b/src/channels.c
@@ -1495,11 +1495,16 @@ error:
  */
 int ssh_channel_request_pty_size(ssh_channel channel, const char *terminal,
     int col, int row) {
-  ssh_session session = channel->session;
+  ssh_session session;
   ssh_string term = NULL;
   ssh_buffer buffer = NULL;
   int rc = SSH_ERROR;
 
+  if (channel == NULL) {
+      return SSH_ERROR;
+  }
+  session = channel->session;
+
   enter_function();
 #ifdef WITH_SSH1
   if (channel->version==1) {