diff --git a/src/main/connection.c b/src/main/connection.c
index f54363e..c853486 100644
--- a/src/main/connection.c
+++ b/src/main/connection.c
@@ -160,11 +160,13 @@ static void con_iostream_close(liConnection *con) { /* force close */
 		con->info.aborted = TRUE;
 		con->con_sock.callbacks->finish(con, TRUE);
 	}
+	assert(NULL == con->con_sock.data);
 }
 static void con_iostream_shutdown(liConnection *con) { /* (try) regular shutdown */
 	if (con->con_sock.callbacks) {
 		con->con_sock.callbacks->finish(con, FALSE);
 	}
+	assert(NULL == con->con_sock.data);
 }
 
 
diff --git a/src/main/stream_simple_socket.c b/src/main/stream_simple_socket.c
index 4bb9fba..348e9df 100644
--- a/src/main/stream_simple_socket.c
+++ b/src/main/stream_simple_socket.c
@@ -108,11 +108,11 @@ static void stream_simple_socket_write_throttle_notify(liThrottleState *state, g
 static void stream_simple_socket_write(liIOStream *stream) {
 	liNetworkStatus res;
 	liChunkQueue *raw_out = stream->stream_out.out;
-	liChunkQueue *from = stream->stream_out.source->out;
+	liChunkQueue *from = (NULL != stream->stream_out.source) ? stream->stream_out.source->out : NULL;
 	int fd = li_event_io_fd(&stream->io_watcher);
 	liWorker *wrk = li_worker_from_iostream(stream);
 
-	li_chunkqueue_steal_all(raw_out, from);
+	if (NULL != from) li_chunkqueue_steal_all(raw_out, from);
 
 	if (raw_out->length > 0) {
 		static const goffset WRITE_MAX = 256*1024; /* 256kB */
diff --git a/src/modules/mod_gnutls.c b/src/modules/mod_gnutls.c
index ca5b1db..f1a7d1b 100644
--- a/src/modules/mod_gnutls.c
+++ b/src/modules/mod_gnutls.c
@@ -197,6 +197,7 @@ static void gnutlc_tcp_finished(liConnection *con, gboolean aborted) {
 	if (NULL != conctx) {
 		assert(con == conctx->con);
 		close_cb(conctx->tls_filter, conctx);
+		assert(NULL == con->con_sock.data);
 	}
 
 	{