diff --git a/bin/dig/host.c b/bin/dig/host.c
index 6debe59660..011587a5a6 100644
--- a/bin/dig/host.c
+++ b/bin/dig/host.c
@@ -854,6 +854,7 @@ parse_args(bool is_batchfile, int argc, char **argv) {
 			break;
 		case 'p':
 			port = atoi(isc_commandline_argument);
+			port_set = true;
 			break;
 		}
 	}
diff --git a/bin/dig/nslookup.c b/bin/dig/nslookup.c
index 67ae315610..a0f508d75a 100644
--- a/bin/dig/nslookup.c
+++ b/bin/dig/nslookup.c
@@ -582,6 +582,7 @@ set_port(const char *value) {
 	isc_result_t result = parse_uint(&n, value, 65535, "port");
 	if (result == ISC_R_SUCCESS) {
 		port = (uint16_t)n;
+		port_set = true;
 	}
 }