diff --git a/panda/src/express/multifile.cxx b/panda/src/express/multifile.cxx
index 2ec152f1e9..8dd44b7415 100644
--- a/panda/src/express/multifile.cxx
+++ b/panda/src/express/multifile.cxx
@@ -575,17 +575,18 @@ write(Filename name) {
 //		 Advances the start pointer as it writes.
 ////////////////////////////////////////////////////////////////////
 bool Multifile::
-write(char *&start, int &size) {
+write(char *&start, int &size, const Filename &rel_path) {
   // Make sure we have a complete header first
   if (parse_header(start, size) == false)
     return false;
 
+  if (_current_mfile == (Memfile *)0L)
+    _current_mfile = new Memfile;
+
   while (_num_mfiles > 0) {
-    if (_current_mfile == (Memfile *)0L)
-      _current_mfile = new Memfile;
-    if (_current_mfile->write(start, size) == true) {
+    if (_current_mfile->write(start, size, rel_path) == true) {
       _num_mfiles--;
-      delete _current_mfile;
+      _current_mfile->reset();
     } else
       return false;
   }
diff --git a/panda/src/express/multifile.h b/panda/src/express/multifile.h
index 21b787097c..ac823443c4 100644
--- a/panda/src/express/multifile.h
+++ b/panda/src/express/multifile.h
@@ -44,7 +44,7 @@ PUBLISHED:
 
   bool read(Filename &name);
   bool write(Filename name);
-  bool write(char *&start, int &size);
+  bool write(char *&start, int &size, const Filename &rel_path = "");
   bool write_extract(char *&start, int &size, const Filename &rel_path = "");
   bool extract(const Filename &name, const Filename &rel_path = "");
   void extract_all(const Filename &rel_path = "");