diff --git a/backend/ibex/data_source/imas_python_source.py b/backend/ibex/data_source/imas_python_source.py
index 0471bee..3658229 100644
--- a/backend/ibex/data_source/imas_python_source.py
+++ b/backend/ibex/data_source/imas_python_source.py
@@ -58,6 +58,10 @@ def data_serializer_custom(self, obj):
             return obj.value
         if isinstance(obj, np.ndarray) and not obj.flags.c_contiguous:
             return np.ascontiguousarray(obj)
+        if isinstance(obj, (np.ndarray, IDSNumericArray)):  # np.arrays with not supported dtype
+            return obj.tolist()
+        if isinstance(obj, complex):  # not supported dtype extracted from np.array
+            return (obj.real, obj.imag)
         raise TypeError
 
     def _open_entry(self, uri: str) -> imas.DBEntry: