diff --git a/lib/formats/json.cpp b/lib/formats/json.cpp
index 086738e22..df09b2dd1 100644
--- a/lib/formats/json.cpp
+++ b/lib/formats/json.cpp
@@ -54,11 +54,15 @@ static json_t * json_pack_timestamps(struct io *io, struct sample *smp)
 {
 	json_t *json_ts = json_object();
 
-	if (io->flags & smp->flags & SAMPLE_HAS_TS_ORIGIN)
-		json_object_set(json_ts, "origin", json_pack("[ I, I ]", smp->ts.origin.tv_sec, smp->ts.origin.tv_nsec));
+	if (io->flags & SAMPLE_HAS_TS_ORIGIN) {
+		if (smp->flags & SAMPLE_HAS_TS_ORIGIN)
+			json_object_set(json_ts, "origin", json_pack("[ I, I ]", smp->ts.origin.tv_sec, smp->ts.origin.tv_nsec));
+	}
 
-	if (io->flags & smp->flags & SAMPLE_HAS_TS_RECEIVED)
-		json_object_set(json_ts, "received", json_pack("[ I, I ]", smp->ts.received.tv_sec, smp->ts.received.tv_nsec));
+	if (io->flags & SAMPLE_HAS_TS_RECEIVED) {
+		if (smp->flags & SAMPLE_HAS_TS_RECEIVED)
+			json_object_set(json_ts, "received", json_pack("[ I, I ]", smp->ts.received.tv_sec, smp->ts.received.tv_nsec));
+	}
 
 	return json_ts;
 }
@@ -101,13 +105,15 @@ static int json_pack_sample(struct io *io, json_t **j, struct sample *smp)
 
 	json_smp = json_pack_ex(&err, 0, "{ s: o }", "ts", json_pack_timestamps(io, smp));
 
-	if (io->flags & smp->flags & SAMPLE_HAS_SEQUENCE) {
-		json_t *json_sequence = json_integer(smp->sequence);
+	if (io->flags & SAMPLE_HAS_SEQUENCE) {
+		if (smp->flags & SAMPLE_HAS_SEQUENCE) {
+			json_t *json_sequence = json_integer(smp->sequence);
 
-		json_object_set(json_smp, "sequence", json_sequence);
+			json_object_set(json_smp, "sequence", json_sequence);
+		}
 	}
 
-	if (io->flags & smp->flags & SAMPLE_HAS_DATA) {
+	if (io->flags & SAMPLE_HAS_DATA) {
 		json_t *json_data = json_array();
 
 		for (unsigned i = 0; i < smp->length; i++) {