diff --git a/setup.h.in b/setup.h.in
index a85bc91fbf..4fcf5acb97 100644
--- a/setup.h.in
+++ b/setup.h.in
@@ -779,6 +779,10 @@
  * Use the mdi architecture
  */
 #define wxUSE_MDI_ARCHITECTURE 0
+/*
+ * Use MDI
+ */
+#define wxUSE_MDI 0
 /*
  * Use the document/view architecture
  */