diff --git a/dvb/dvb_tables.c b/dvb/dvb_tables.c
index a5799362..1929f2e2 100644
--- a/dvb/dvb_tables.c
+++ b/dvb/dvb_tables.c
@@ -790,7 +790,9 @@ dvb_pmt_callback(th_dvb_mux_instance_t *tdmi, uint8_t *ptr, int len,
 		 uint8_t tableid, void *opaque)
 {
   th_transport_t *t = opaque;
+  pthread_mutex_lock(&t->tht_stream_mutex);
   psi_parse_pmt(t, ptr, len, 1);
+  pthread_mutex_unlock(&t->tht_stream_mutex);
 }