diff --git a/dom/base/FileReader.cpp b/dom/base/FileReader.cpp
index 273e192d0c..7a8cb31d6e 100644
--- a/dom/base/FileReader.cpp
+++ b/dom/base/FileReader.cpp
@@ -775,6 +775,7 @@ FileReader::Shutdown()
     mAsyncStream = nullptr;
   }
 
+  ClearProgressEventTimer();
   FreeFileData();
   mResultArrayBuffer = nullptr;