diff --git a/panda/src/gobj/vertexDataSaveFile.cxx b/panda/src/gobj/vertexDataSaveFile.cxx
index f66d51b0f2..6d710f5484 100644
--- a/panda/src/gobj/vertexDataSaveFile.cxx
+++ b/panda/src/gobj/vertexDataSaveFile.cxx
@@ -194,6 +194,7 @@ write_data(const unsigned char *data, size_t size, bool compressed) {
 
   PT(VertexDataSaveBlock) block = (VertexDataSaveBlock *)SimpleAllocator::do_alloc(size);
   if (block != (VertexDataSaveBlock *)NULL) {
+    _total_file_size = max(_total_file_size, block->get_start() + size);
     block->set_compressed(compressed);
 
 #ifdef _WIN32
@@ -240,8 +241,6 @@ write_data(const unsigned char *data, size_t size, bool compressed) {
       size -= result;
     }
 #endif  // _WIN32
-
-    _total_file_size = max(_total_file_size, block->get_start() + size);
   }
 
   return block;
diff --git a/panda/src/gobj/vertexDataSaveFile.h b/panda/src/gobj/vertexDataSaveFile.h
index 1db5c347c9..b0fd3802f3 100644
--- a/panda/src/gobj/vertexDataSaveFile.h
+++ b/panda/src/gobj/vertexDataSaveFile.h
@@ -44,11 +44,13 @@ public:
                      size_t max_size);
   ~VertexDataSaveFile();
 
+PUBLISHED:
   INLINE bool is_valid() const;
 
   INLINE size_t get_total_file_size() const;
   INLINE size_t get_used_file_size() const;
-  
+
+public:  
   PT(VertexDataSaveBlock) write_data(const unsigned char *data, size_t size,
                                      bool compressed);
   bool read_data(unsigned char *data, size_t size,