diff --git a/netwerk/streamconv/converters/nsDirIndex.cpp b/netwerk/streamconv/converters/nsDirIndex.cpp
index 47dcbbbd44c..59aad9fd5bc 100644
--- a/netwerk/streamconv/converters/nsDirIndex.cpp
+++ b/netwerk/streamconv/converters/nsDirIndex.cpp
@@ -45,7 +45,7 @@ NS_IMPL_THREADSAFE_ISUPPORTS1(nsDirIndex,
                               nsIDirIndex)
 
 nsDirIndex::nsDirIndex() : mType(TYPE_UNKNOWN),
-                           mSize(LL_INIT(0, -1)),
+                           mSize(LL_MAXUINT),
                            mLastModified(-1) {
 }
 
diff --git a/netwerk/streamconv/converters/nsDirIndexParser.cpp b/netwerk/streamconv/converters/nsDirIndexParser.cpp
index 6b4c7d5a341..08914a5fb34 100644
--- a/netwerk/streamconv/converters/nsDirIndexParser.cpp
+++ b/netwerk/streamconv/converters/nsDirIndexParser.cpp
@@ -331,7 +331,7 @@ nsDirIndexParser::ParseData(nsIDirIndex *aIdx, char* aDataStr) {
         if (status == 1)
           aIdx->SetSize(len);
         else
-          aIdx->SetSize(LL_INIT(0, -1)); // -1 means unknown
+          aIdx->SetSize(LL_MAXUINT); // LL_MAXUINT means unknown
       }
       break;
     case FIELD_LASTMODIFIED:
diff --git a/netwerk/streamconv/converters/nsIndexedToHTML.cpp b/netwerk/streamconv/converters/nsIndexedToHTML.cpp
index cb4db107525..2b7a22a6cad 100644
--- a/netwerk/streamconv/converters/nsIndexedToHTML.cpp
+++ b/netwerk/streamconv/converters/nsIndexedToHTML.cpp
@@ -549,7 +549,7 @@ nsIndexedToHTML::OnIndexAvailable(nsIRequest *aRequest,
     PRInt64 size;
     aIndex->GetSize(&size);
     
-    if (LL_NE(size, LL_INIT(0, -1)) &&
+    if (LL_NE(PRUint64(size), LL_MAXUINT) &&
         type != nsIDirIndex::TYPE_DIRECTORY &&
         type != nsIDirIndex::TYPE_SYMLINK) {
         nsAutoString  sizeString;
diff --git a/xpfe/components/directory/nsDirectoryViewer.cpp b/xpfe/components/directory/nsDirectoryViewer.cpp
index afa49fa8b27..4943a8bb1cf 100644
--- a/xpfe/components/directory/nsDirectoryViewer.cpp
+++ b/xpfe/components/directory/nsDirectoryViewer.cpp
@@ -481,7 +481,7 @@ nsHTTPIndex::OnIndexAvailable(nsIRequest* aRequest, nsISupports *aContext,
       PRInt64 size;
       rv = aIndex->GetSize(&size);
       if (NS_FAILED(rv)) return rv;
-      if (LL_NE(size, LL_INIT(0, -1))) {
+      if (LL_NE(PRUint64(size), LL_MAXUINT)) {
         PRInt32 intSize;
         LL_L2I(intSize, size);
         // XXX RDF should support 64 bit integers (bug 240160)