diff --git a/src/Make_ming.mak b/src/Make_ming.mak
index ca50d37..1392d87 100644
--- a/src/Make_ming.mak
+++ b/src/Make_ming.mak
@@ -51,7 +51,9 @@
 # set to yes to enable OLE support
 OLE=no
 # Set the default $(WINVER) to make it work with pre-Win2k
+ifndef WINVER
 WINVER = 0x0400
+endif
 # Set to yes to enable Cscope support
 CSCOPE=yes
 # Set to yes to enable Netbeans support