diff --git a/stream/mts/encoder.go b/stream/mts/encoder.go
index 78a841f5..74df4746 100644
--- a/stream/mts/encoder.go
+++ b/stream/mts/encoder.go
@@ -178,7 +178,7 @@ func (e *Encoder) TimeBasedPsi(b bool, sendCount int) {
 // sending them to the output channel.
 func (e *Encoder) Encode(nalu []byte) error {
 	now := time.Now()
-	if (e.timeBasedPsi && (now.Sub(e.psiLastTime) > psiInterval)) || e.pktCount >= e.psiSendCount {
+	if (e.timeBasedPsi && (now.Sub(e.psiLastTime) > psiInterval)) || (!e.timeBasedPsi && (e.pktCount >= e.psiSendCount)) {
 		e.pktCount = 0
 		err := e.writePSI()
 		if err != nil {