diff --git a/sohstationviewer/model/reftek/reftek_data/core.py b/sohstationviewer/model/reftek/reftek_data/core.py
index b4b35704f7c2a6da843a89cfa7c66dca00731c0d..ddc08d0ba45cd1235697879bbbdae0ece8bfc890 100644
--- a/sohstationviewer/model/reftek/reftek_data/core.py
+++ b/sohstationviewer/model/reftek/reftek_data/core.py
@@ -197,9 +197,9 @@ class Reftek130(obspy_rt130_core.Reftek130):
                         # numbers (namely, appending a negative number with 1s
                         # does not change its value), we do not have to care
                         # about the actual encoding type of the stored packets.
-                        sample_data = (packets_['payload'][:, :4])
-                        sample_data = sample_data.view(np.dtype('>i4')).squeeze()
-                        npts = len(sample_data)
+                        sample_data = np.asarray(packets_['payload'][:, :4])
+                        sample_data = sample_data.view(np.dtype('>i4')).squeeze(axis=-1)
+                        npts = sample_data.size
                     tr = DiscontinuousTrace(
                         data=sample_data, header=copy.deepcopy(header),
                         times=(packets_['time'] / 10**9).round(3)