diff --git a/netwerk/streamconv/converters/nsDirIndex.cpp b/netwerk/streamconv/converters/nsDirIndex.cpp
index 46aabbb2270..cb7c81d41c5 100644
--- a/netwerk/streamconv/converters/nsDirIndex.cpp
+++ b/netwerk/streamconv/converters/nsDirIndex.cpp
@@ -68,5 +68,5 @@ nsDirIndex::SetDescription(const PRUnichar* aDescription) {
 }
 
 NS_IMPL_GETSET(nsDirIndex, Size, int64_t, mSize)
-NS_IMPL_GETSET(nsDirIndex, LastModified, int64_t, mLastModified)
+NS_IMPL_GETSET(nsDirIndex, LastModified, PRTime, mLastModified)
 
diff --git a/netwerk/streamconv/converters/nsDirIndex.h b/netwerk/streamconv/converters/nsDirIndex.h
index e411a87ef18..f6f956d5ef7 100644
--- a/netwerk/streamconv/converters/nsDirIndex.h
+++ b/netwerk/streamconv/converters/nsDirIndex.h
@@ -23,5 +23,5 @@ protected:
     nsXPIDLCString mLocation;
     nsString mDescription;
     int64_t mSize;
-    int64_t mLastModified;
+    PRTime mLastModified;
 };
diff --git a/netwerk/streamconv/converters/nsIndexedToHTML.cpp b/netwerk/streamconv/converters/nsIndexedToHTML.cpp
index b6d3fd5dc8e..82a49a357d4 100644
--- a/netwerk/streamconv/converters/nsIndexedToHTML.cpp
+++ b/netwerk/streamconv/converters/nsIndexedToHTML.cpp
@@ -951,7 +951,7 @@ nsIndexedToHTML::OnIndexAvailable(nsIRequest *aRequest,
         pushBuffer.AppendLiteral("></td>\n <td>");
     } else {
         pushBuffer.AppendLiteral(" sortable-data=\"");
-        pushBuffer.AppendInt(t);
+        pushBuffer.AppendInt(static_cast<int64_t>(t));
         pushBuffer.AppendLiteral("\">");
         nsAutoString formatted;
         mDateTime->FormatPRTime(nullptr,