diff --git a/samples/mfc/makefile.vc b/samples/mfc/makefile.vc
index 569d33850c..a8d3918091 100644
--- a/samples/mfc/makefile.vc
+++ b/samples/mfc/makefile.vc
@@ -13,6 +13,7 @@ WXDIR = $(WXWIN)
 
 PROGRAM=mfctest
 OBJECTS = $(PROGRAM).obj
+EXTRAFLAGS=/D_AFXDLL
 
 !include $(WXDIR)\src\makeprog.vc