diff --git a/src/numericsort.c b/src/numericsort.c
index be1b518ff..9aff407aa 100644
--- a/src/numericsort.c
+++ b/src/numericsort.c
@@ -48,6 +48,8 @@
 #      include <ndir.h>
 #    endif /* HAVE_NDIR_H */
 #  endif /* HAVE_DIRENT_H */
+#else /* For WIN32 variants */
+#  include <FL/filename.H>
 #endif /* !WIN32 || __CYGWIN__ */
 
 /*