diff --git a/src/actsim_agent/downloader.cpp b/src/actsim_agent/downloader.cpp
index ee79ff2..6d1cc75 100644
--- a/src/actsim_agent/downloader.cpp
+++ b/src/actsim_agent/downloader.cpp
@@ -36,6 +36,7 @@
 #include <functional>
 #include <unordered_set>
 #include <vector>
+#include "actsim_agent.hpp"
 #include "agent_artifact.hpp"
 #include "cluster/db_types.hpp"
 #include "pqxx/prepared_statement.hxx"
@@ -79,6 +80,8 @@ void Downloader::thread_run() {
         // make sure we weren't woken up because the program closed
         if (!this->interface.running()) break;
 
+        if (this->interface.get_buffer_space() < DOWNLOAD_BUFFER * 0.8) continue;
+
         // if the download buffer is not full, fetch some more tasks
         if (!this->fetch_tasks(this->interface.get_buffer_space())) {
             // we can sleep for a certain amount of time, nothing to do