diff --git a/src/rinex.c b/src/rinex.c
index 9761b3be3393989c42a93e1fdfcb55bb8bc6d8e9..e05fcc26ad7af133c62aef15d404424b4a1aee79 100644
--- a/src/rinex.c
+++ b/src/rinex.c
@@ -847,6 +847,8 @@ static int addobsdata(obs_t *obs, const obsd_t *data)
         obs->data=obs_data;
     }
     obs->data[obs->n++]=*data;
+    obs->data[obs->n - 1].timevalid = 0;
+    obs->data[obs->n - 1].freq = '\0';
     return 1;
 }
 /* set system mask -----------------------------------------------------------*/