diff --git a/lib/logvisor.cpp b/lib/logvisor.cpp
index e7e1f17..297df93 100644
--- a/lib/logvisor.cpp
+++ b/lib/logvisor.cpp
@@ -760,6 +760,7 @@ struct FileLogger : public ILogger {
   }
   virtual void closeFile() {
     if (fp) {
+      std::fflush(fp);
       std::fclose(fp);
       fp = nullptr;
     }