diff --git a/src/vim.h b/src/vim.h
index f030282..a771aba 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -410,6 +410,10 @@
 
 #include <assert.h>
 
+#ifdef HAVE_WCTYPE_H
+# include <wctype.h>
+#endif
+
 /* ================ end of the header file puzzle =============== */
 
 /*