Wrap <stdint.h> in #ifdef HAVE_STDINT_H.
diff --git a/xmss_wots.c b/xmss_wots.c
index 4120acf..9f1900f 100644
--- a/xmss_wots.c
+++ b/xmss_wots.c
@@ -8,7 +8,9 @@
 #include "includes.h"
 
 #include <stdlib.h>
+#ifdef HAVE_STDINT_H
 #include <stdint.h>
+#endif
 #include <limits.h>
 #include "xmss_commons.h"
 #include "xmss_hash.h"