diff --git a/rfb/FileWriter.cxx b/rfb/FileWriter.cxx
index 6503cc9..9d8c4a5 100644
--- a/rfb/FileWriter.cxx
+++ b/rfb/FileWriter.cxx
@@ -27,7 +27,7 @@
 
 FileWriter::FileWriter()
 {
-  strcpy(m_szMode, "w");
+  strcpy(m_szMode, "wb");
 }
 
 bool