diff --git a/decompressing_file_writer.h b/decompressing_file_writer.h
index 6f12e87..cd8e294 100644
--- a/decompressing_file_writer.h
+++ b/decompressing_file_writer.h
@@ -36,7 +36,7 @@
   // stream, after the entire stream has been written to this object,
   // the entire decompressed stream will have been written to the
   // underlying FileWriter.
-  virtual int Write(const void* bytes, size_t count);
+  virtual ssize_t Write(const void* bytes, size_t count);
 
   virtual int Close() {
     return next_->Close();