diff --git a/bin/tests/test_client.c b/bin/tests/test_client.c
index 10517f24c7..edc6d66320 100644
--- a/bin/tests/test_client.c
+++ b/bin/tests/test_client.c
@@ -232,7 +232,7 @@ parse_options(int argc, char **argv) {
 			break;
 
 		default:
-			INSIST(0);
+			UNREACHABLE();
 		}
 	}
 
diff --git a/bin/tests/test_server.c b/bin/tests/test_server.c
index 066dcf9e7f..2d80db4457 100644
--- a/bin/tests/test_server.c
+++ b/bin/tests/test_server.c
@@ -152,7 +152,7 @@ parse_options(int argc, char **argv) {
 			break;
 
 		default:
-			INSIST(0);
+			UNREACHABLE();
 		}
 	}
 
diff --git a/cocci/unreachable.spatch b/cocci/unreachable.spatch
index 100f1a0abe..84c0c344bb 100644
--- a/cocci/unreachable.spatch
+++ b/cocci/unreachable.spatch
@@ -11,3 +11,9 @@
 -   INSIST(0);
 -   ISC_UNREACHABLE();
 +   UNREACHABLE();
+
+@@
+@@
+
+- UNREACHABLE();
+  UNREACHABLE();
diff --git a/lib/dns/rpz.c b/lib/dns/rpz.c
index 4fa7501e32..aa611d7c73 100644
--- a/lib/dns/rpz.c
+++ b/lib/dns/rpz.c
@@ -2590,7 +2590,7 @@ dns_rpz_find_ip(dns_rpz_zones_t *rpzs, dns_rpz_type_t rpz_type,
 			zbits &= have.nsipv4;
 			break;
 		default:
-			INSIST(0);
+			UNREACHABLE();
 			break;
 		}
 	} else if (netaddr->family == AF_INET6) {
@@ -2616,7 +2616,7 @@ dns_rpz_find_ip(dns_rpz_zones_t *rpzs, dns_rpz_type_t rpz_type,
 			zbits &= have.nsipv6;
 			break;
 		default:
-			INSIST(0);
+			UNREACHABLE();
 			break;
 		}
 	} else {
diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
index 2bce1c7d7c..17d2004685 100644
--- a/lib/isc/netmgr/netmgr.c
+++ b/lib/isc/netmgr/netmgr.c
@@ -2273,7 +2273,7 @@ isc__nm_process_sock_buffer(isc_nmsocket_t *sock) {
 			}
 			break;
 		default:
-			INSIST(0);
+			UNREACHABLE();
 		}
 	}
 }
@@ -2799,7 +2799,6 @@ isc__nmsocket_reset(isc_nmsocket_t *sock) {
 		REQUIRE(sock->parent == NULL);
 		break;
 	default:
-		INSIST(0);
 		UNREACHABLE();
 		break;
 	}
@@ -3493,7 +3492,6 @@ isc_nm_set_maxage(isc_nmhandle_t *handle, const uint32_t ttl) {
 	case isc_nm_tlssocket:
 #endif /* HAVE_LIBNGHTTP2 */
 	default:
-		INSIST(0);
 		UNREACHABLE();
 		break;
 	}
diff --git a/lib/isc/rwlock.c b/lib/isc/rwlock.c
index c76ea74dda..2691a44de4 100644
--- a/lib/isc/rwlock.c
+++ b/lib/isc/rwlock.c
@@ -82,7 +82,7 @@ isc_rwlock_trylock(isc_rwlock_t *rwl, isc_rwlocktype_t type) {
 		}
 		break;
 	default:
-		INSIST(0);
+		UNREACHABLE();
 	}
 
 	switch (ret) {
diff --git a/lib/isc/timer.c b/lib/isc/timer.c
index f833000601..5d54e3843a 100644
--- a/lib/isc/timer.c
+++ b/lib/isc/timer.c
@@ -117,7 +117,6 @@ schedule(isc_timer_t *timer, isc_time_t *now, bool signal_ok) {
 		due = timer->idle;
 		break;
 	default:
-		INSIST(0);
 		UNREACHABLE();
 	}
 
@@ -425,7 +424,6 @@ dispatch(isc_timermgr_t *manager, isc_time_t *now) {
 			need_schedule = false;
 			break;
 		default:
-			INSIST(0);
 			UNREACHABLE();
 		}
 
diff --git a/lib/ns/query.c b/lib/ns/query.c
index cb1a579307..b9e76eb897 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -293,7 +293,7 @@ get_hooktab(query_ctx_t *qctx) {
 				result = _res;                      \
 				goto cleanup;                       \
 			default:                                    \
-				INSIST(0);                          \
+				UNREACHABLE();                      \
 			}                                           \
 		}                                                   \
 	} while (false)