diff --git a/mozilla/content/base/src/nsGenericElement.cpp b/mozilla/content/base/src/nsGenericElement.cpp
index dde608a3bb5..307ec34ceb0 100644
--- a/mozilla/content/base/src/nsGenericElement.cpp
+++ b/mozilla/content/base/src/nsGenericElement.cpp
@@ -366,8 +366,7 @@ nsCheapVoidArray::SwitchToVector()
 {
   void* child = GetSingleChild();
 
-  // XXX Probably should be nsAutoVoidArray to avoid extra alloc - check bloat!
-  mChildren = (void*)new nsVoidArray();
+  mChildren = (void*)new nsAutoVoidArray();
   nsVoidArray* vector = GetChildVector();
   if (vector && child) {
     vector->AppendElement(child);
diff --git a/mozilla/content/xul/document/src/nsXULContentSink.cpp b/mozilla/content/xul/document/src/nsXULContentSink.cpp
index a7884a4314d..3572e3c23b3 100644
--- a/mozilla/content/xul/document/src/nsXULContentSink.cpp
+++ b/mozilla/content/xul/document/src/nsXULContentSink.cpp
@@ -227,8 +227,8 @@ protected:
     protected:
         struct Entry {
             nsXULPrototypeNode* mNode;
-            // a LOT of nodes have children, but leave for now
-            nsVoidArray         mChildren;
+            // a LOT of nodes have children; preallocate for 8
+            nsAutoVoidArray     mChildren;
             State               mState;
             Entry*              mNext;
         };