diff --git a/lib/dns/keymgr.c b/lib/dns/keymgr.c
index 3a18b26224..f34753afa4 100644
--- a/lib/dns/keymgr.c
+++ b/lib/dns/keymgr.c
@@ -319,7 +319,7 @@ keymgr_prepublication_time(dns_dnsseckey_t *key, dns_kasp_t *kasp,
 			return 0;
 		}
 
-		if (ISC_OVERFLOW_ADD(active, klifetime, &retire)) {
+		if (ckd_add(&retire, active, klifetime)) {
 			log_key_overflow(key->key, "retire");
 			retire = UINT32_MAX;
 		}
@@ -424,7 +424,7 @@ keymgr_key_update_lifetime(dns_dnsseckey_t *key, dns_kasp_t *kasp,
 			uint32_t a = now;
 			uint32_t inactive;
 			(void)dst_key_gettime(key->key, DST_TIME_ACTIVATE, &a);
-			if (ISC_OVERFLOW_ADD(a, lifetime, &inactive)) {
+			if (ckd_add(&inactive, a, lifetime)) {
 				log_key_overflow(key->key, "inactive");
 				inactive = UINT32_MAX;
 			}
@@ -1904,7 +1904,7 @@ keymgr_key_rollover(dns_kasp_key_t *kaspkey, dns_dnsseckey_t *active_key,
 	if (lifetime > 0) {
 		uint32_t inactive;
 
-		if (ISC_OVERFLOW_ADD(active, lifetime, &inactive)) {
+		if (ckd_add(&inactive, active, lifetime)) {
 			log_key_overflow(new_key->key, "inactive");
 			inactive = UINT32_MAX;
 		}
diff --git a/lib/dns/rdataslab.c b/lib/dns/rdataslab.c
index 2297418665..6991fe9187 100644
--- a/lib/dns/rdataslab.c
+++ b/lib/dns/rdataslab.c
@@ -173,7 +173,7 @@ makeslab(dns_rdataset_t *rdataset, isc_mem_t *mctx, isc_region_t *region,
 	 */
 	nalloc = nitems;
 
-	RUNTIME_CHECK(!ISC_OVERFLOW_MUL(nalloc, sizeof(rdata[0]), &rdatasize));
+	RUNTIME_CHECK(!ckd_mul(&rdatasize, nalloc, sizeof(rdata[0])));
 	rdata = isc_mem_get(mctx, rdatasize);
 
 	/*
diff --git a/lib/isc/include/isc/overflow.h b/lib/isc/include/isc/overflow.h
index bd8e4eec73..38aa8fee9f 100644
--- a/lib/isc/include/isc/overflow.h
+++ b/lib/isc/include/isc/overflow.h
@@ -17,63 +17,45 @@
 
 #include <isc/util.h>
 
-/*
- * It is awkward to support signed numbers as well, so keep it simple
- * (with a safety check).
- */
-#define ISC_OVERFLOW_IS_UNSIGNED(a)                                      \
-	({                                                               \
-		STATIC_ASSERT((typeof(a))-1 > 0,                         \
-			      "overflow checks require unsigned types"); \
-		(a);                                                     \
+#if HAVE_STDCKDINT_H
+#include <stdckdint.h>
+
+#else /* HAVE_STDCKDINT_H */
+
+#define ckd_mul(cp, a, b) __builtin_mul_overflow(a, b, cp)
+#define ckd_add(cp, a, b) __builtin_add_overflow(a, b, cp)
+#define ckd_sub(cp, a, b) __builtin_sub_overflow(a, b, cp)
+
+#endif /* HAVE_STDCKDINT_H */
+
+#define ISC_CHECKED_MUL(a, b)                             \
+	({                                                \
+		typeof(a) _c;                             \
+		bool	  _overflow = ckd_mul(&_c, a, b); \
+		INSIST(!_overflow);                       \
+		_c;                                       \
 	})
 
-#define ISC_OVERFLOW_UINT_MAX(a) ISC_OVERFLOW_IS_UNSIGNED((typeof(a))-1)
-
-#define ISC_OVERFLOW_UINT_MIN(a) ISC_OVERFLOW_IS_UNSIGNED(0)
-
-/*
- * Return true on overflow, e.g.
- *
- *	bool overflow = ISC_OVERFLOW_MUL(count, sizeof(array[0]), &bytes);
- *	INSIST(!overflow);
- */
-
-#define ISC_OVERFLOW_MUL(a, b, cp) __builtin_mul_overflow(a, b, cp)
-
-#define ISC_OVERFLOW_ADD(a, b, cp) __builtin_add_overflow(a, b, cp)
-
-#define ISC_OVERFLOW_SUB(a, b, cp) __builtin_sub_overflow(a, b, cp)
-
-#define ISC_CHECKED_MUL(a, b)                                      \
-	({                                                         \
-		typeof(a) _c;                                      \
-		bool	  _overflow = ISC_OVERFLOW_MUL(a, b, &_c); \
-		INSIST(!_overflow);                                \
-		_c;                                                \
+#define ISC_CHECKED_ADD(a, b)                             \
+	({                                                \
+		typeof(a) _c;                             \
+		bool	  _overflow = ckd_add(&_c, a, b); \
+		INSIST(!_overflow);                       \
+		_c;                                       \
 	})
 
-#define ISC_CHECKED_ADD(a, b)                                      \
-	({                                                         \
-		typeof(a) _c;                                      \
-		bool	  _overflow = ISC_OVERFLOW_ADD(a, b, &_c); \
-		INSIST(!_overflow);                                \
-		_c;                                                \
+#define ISC_CHECKED_SUB(a, b)                             \
+	({                                                \
+		typeof(a) _c;                             \
+		bool	  _overflow = ckd_sub(&_c, a, b); \
+		INSIST(!_overflow);                       \
+		_c;                                       \
 	})
 
-#define ISC_CHECKED_SUB(a, b)                                     \
-	({                                                        \
-		typeof(a) _c;                                     \
-		bool	  _overflow = ISC_OVERFLOW_SUB(a, b, cp); \
-		INSIST(!_overflow);                               \
-		_c;                                               \
-	})
-
-#define ISC_CHECKED_MUL_ADD(a, b, c)                              \
-	({                                                        \
-		size_t _d;                                        \
-		bool   _overflow = ISC_OVERFLOW_MUL(a, b, &_d) || \
-				 ISC_OVERFLOW_ADD(_d, c, &_d);    \
-		INSIST(!_overflow);                               \
-		_d;                                               \
+#define ISC_CHECKED_MUL_ADD(a, b, c)                                          \
+	({                                                                    \
+		size_t _d;                                                    \
+		bool   _overflow = ckd_mul(&_d, a, b) || ckd_add(&_d, _d, c); \
+		INSIST(!_overflow);                                           \
+		_d;                                                           \
 	})
diff --git a/lib/isc/time.c b/lib/isc/time.c
index fc47e6c48f..90afabfc42 100644
--- a/lib/isc/time.c
+++ b/lib/isc/time.c
@@ -190,7 +190,7 @@ isc_time_add(const isc_time_t *t, const isc_interval_t *i, isc_time_t *result) {
 	REQUIRE(t->nanoseconds < NS_PER_SEC && i->nanoseconds < NS_PER_SEC);
 
 	/* Seconds */
-	if (ISC_OVERFLOW_ADD(t->seconds, i->seconds, &result->seconds)) {
+	if (ckd_add(&result->seconds, t->seconds, i->seconds)) {
 		return ISC_R_RANGE;
 	}
 
@@ -214,7 +214,7 @@ isc_time_subtract(const isc_time_t *t, const isc_interval_t *i,
 	REQUIRE(t->nanoseconds < NS_PER_SEC && i->nanoseconds < NS_PER_SEC);
 
 	/* Seconds */
-	if (ISC_OVERFLOW_SUB(t->seconds, i->seconds, &result->seconds)) {
+	if (ckd_sub(&result->seconds, t->seconds, i->seconds)) {
 		return ISC_R_RANGE;
 	}
 
diff --git a/meson.build b/meson.build
index 133e6d1e8f..736f99d8fe 100644
--- a/meson.build
+++ b/meson.build
@@ -525,6 +525,7 @@ foreach h : [
     'net/if6.h',
     'net/route.h',
     'regex.h',
+    'stdckdint.h',
     'sys/mman.h',
     'sys/select.h',
     'sys/sockio.h',