diff --git a/mozilla/modules/libjar/nsJAR.cpp b/mozilla/modules/libjar/nsJAR.cpp
index 7cc4dccbe59..f3c0d1da5be 100644
--- a/mozilla/modules/libjar/nsJAR.cpp
+++ b/mozilla/modules/libjar/nsJAR.cpp
@@ -199,6 +199,7 @@ nsJAR::Close()
   }
 
   mParsedManifest = PR_FALSE;
+  mManifestData.Reset();
   mGlobalStatus = JAR_MANIFEST_NOT_PARSED;
   mTotalItemsInManifest = 0;