diff --git a/include/osgDB/OutputStream b/include/osgDB/OutputStream
index 24a55bd4b..61c54d1d9 100644
--- a/include/osgDB/OutputStream
+++ b/include/osgDB/OutputStream
@@ -92,6 +92,7 @@ public:
     // Serialization related functions
     OutputStream& operator<<( bool b ) { _out->writeBool(b); return *this; }
     OutputStream& operator<<( char c ) { _out->writeChar(c); return *this; }
+    OutputStream& operator<<( signed char c) { _out->writeChar(c); return *this; }
     OutputStream& operator<<( unsigned char c ) { _out->writeUChar(c); return *this; }
     OutputStream& operator<<( short s ) { _out->writeShort(s); return *this; }
     OutputStream& operator<<( unsigned short s ) { _out->writeUShort(s); return *this; }