diff --git a/common/rfb/CSecurityNone.h b/common/rfb/CSecurityNone.h
index 54c1016..a7db6e0 100644
--- a/common/rfb/CSecurityNone.h
+++ b/common/rfb/CSecurityNone.h
@@ -22,6 +22,7 @@
 #ifndef __CSECURITYNONE_H__
 #define __CSECURITYNONE_H__
 
+#include <rfb/Security.h>
 #include <rfb/CSecurity.h>
 
 namespace rfb {