diff --git a/netwerk/base/src/nsDirectoryIndexStream.cpp b/netwerk/base/src/nsDirectoryIndexStream.cpp
index f1943fa00646..83ec5c7e5f42 100644
--- a/netwerk/base/src/nsDirectoryIndexStream.cpp
+++ b/netwerk/base/src/nsDirectoryIndexStream.cpp
@@ -165,12 +165,10 @@ nsDirectoryIndexStream::Init(nsIFile* aDir)
     }
 #endif
 
-    mDir = aDir;
-    
     // Sigh. We have to allocate on the heap because there are no
     // assignment operators defined.
     nsCOMPtr<nsISimpleEnumerator> iter;
-    rv = mDir->GetDirectoryEntries(getter_AddRefs(iter));
+    rv = aDir->GetDirectoryEntries(getter_AddRefs(iter));
     if (NS_FAILED(rv)) return rv;
 
     // Now lets sort, because clients expect it that way
@@ -215,7 +213,7 @@ nsDirectoryIndexStream::Init(nsIFile* aDir)
 
     mBuf.Append("300: ");
     nsCAutoString url;
-    rv = net_GetURLSpecFromFile(mDir, url);
+    rv = net_GetURLSpecFromFile(aDir, url);
     if (NS_FAILED(rv)) return rv;
     mBuf.Append(url);
     mBuf.Append('\n');
diff --git a/netwerk/base/src/nsDirectoryIndexStream.h b/netwerk/base/src/nsDirectoryIndexStream.h
index 6e6a3341cd2d..4236b551c051 100644
--- a/netwerk/base/src/nsDirectoryIndexStream.h
+++ b/netwerk/base/src/nsDirectoryIndexStream.h
@@ -51,7 +51,6 @@ protected:
     nsCAutoString mBuf;
     PRInt32 mOffset;
 
-    nsCOMPtr<nsIFile> mDir;
     PRInt32 mPos;
     nsVoidArray mArray;
     
@@ -61,10 +60,16 @@ protected:
     nsCOMPtr<nsITextToSubURI> mTextToSubURI;
 
     nsDirectoryIndexStream();
+    /**
+     * aDir will only be used on the calling thread.
+     */ 
     nsresult Init(nsIFile* aDir);
     virtual ~nsDirectoryIndexStream();
 
 public:
+    /**
+     * aDir will only be used on the calling thread.
+     */ 
     static nsresult
     Create(nsIFile* aDir, nsIInputStream** aStreamResult);