diff --git a/src/vim.h b/src/vim.h
index 25c9d12..1cf7648 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1992,6 +1992,7 @@
 // Note that gui.h is included by structs.h
 
 #include "structs.h"	// defines many structures
+#include "xdiff/xdiff.h"	// TODO: maybe remove this, but this brings in mmfile_t so it can compile
 
 #include "alloc.h"