diff --git a/goldlib/msgidlib/Makefile b/goldlib/msgidlib/Makefile
index 6eb18c1..0b1dc83 100755
--- a/goldlib/msgidlib/Makefile
+++ b/goldlib/msgidlib/Makefile
@@ -7,6 +7,10 @@ TARGET=msgidlib
 include $(TOP)/GNUmakef.inc
 include $(TOP)/GNUmakef.lib
 
+ifeq ($(PLATFORM),lnx)
+CFLAGS+=-DUNIX
+endif
+
 ifeq ($(PLATFORM),be)
 CFLAGS+=-DUNIX=__BEOS__
 endif