diff --git a/common/rfb/d3des.h b/common/rfb/d3des.h
index ea3da44..73adfad 100644
--- a/common/rfb/d3des.h
+++ b/common/rfb/d3des.h
@@ -19,6 +19,10 @@
  *	(GEnie : OUTER; CIS : [71755,204])
  */
 
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
 #define EN0	0	/* MODE == encrypt */
 #define DE1	1	/* MODE == decrypt */
 
@@ -47,5 +51,9 @@
  * into the block at address 'to'.  They can be the same.
  */
 
+#ifdef __cplusplus
+}
+#endif
+
 /* d3des.h V5.09 rwo 9208.04 15:06 Graven Imagery
  ********************************************************************/