diff --git a/decompressing_file_writer.cc b/decompressing_file_writer.cc
old mode 100644
new mode 100755
index 96db010..0a3280d
--- a/decompressing_file_writer.cc
+++ b/decompressing_file_writer.cc
@@ -27,7 +27,7 @@
 //      uLong   reserved;   /* reserved for future use */
 //  } z_stream;
 
-int GzipDecompressingFileWriter::Write(const void* bytes, size_t count) {
+ssize_t GzipDecompressingFileWriter::Write(const void* bytes, size_t count) {
   // Steps:
   // put the data on next_in
   // call inflate until it returns nothing, each time writing what we get