remove undefined behavior warning
diff --git a/skeletons/constr_SET.h b/skeletons/constr_SET.h
index eb61b5a..6a8d077 100644
--- a/skeletons/constr_SET.h
+++ b/skeletons/constr_SET.h
@@ -70,13 +70,13 @@
#define ASN_SET_ISPRESENT2(map_ptr, PR_x) \
(((unsigned int *)(map_ptr)) \
[(PR_x) / (8 * sizeof(unsigned int))] \
- & (1 << ((8 * sizeof(unsigned int)) - 1 \
+ & (1u << ((8 * sizeof(unsigned int)) - 1 \
- ((PR_x) % (8 * sizeof(unsigned int))))))
#define ASN_SET_MKPRESENT(map_ptr, PR_x) \
(((unsigned int *)(map_ptr)) \
[(PR_x) / (8 * sizeof(unsigned int))] \
- |= (1 << ((8 * sizeof(unsigned int)) - 1 \
+ |= (1u << ((8 * sizeof(unsigned int)) - 1 \
- ((PR_x) % (8 * sizeof(unsigned int))))))
#ifdef __cplusplus