diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index 8b1ec633b812f7267e9fdfca6570886d249bbb15..a7ab46f601e7a4f31178df912e93df19a2b8c459 100755
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -1629,7 +1629,11 @@ class Instrument:
             names* (str): attribute names
         """
         for name in names:
-            hdf5.attrs[name] = self.__getattribute__(name)
+            value = self.__getattribute__(name)
+            # Take string representation for non-native types
+            if not isinstance(value, (int, float, np.ndarray)):
+                value = str(value)
+            hdf5.attrs[name] = value
 
     def _write_metadata(self, hdf5):
         """Write relevant object's attributes as metadata on ``hdf5``.