diff --git a/mne/time_frequency/spectrum.py b/mne/time_frequency/spectrum.py
index bd5ed68dd60..3fac0fc0837 100644
--- a/mne/time_frequency/spectrum.py
+++ b/mne/time_frequency/spectrum.py
@@ -228,21 +228,22 @@ def __eq__(self, other):
 
     def __repr__(self):
         """Build string representation of the Spectrum object."""
-        inst_type = self._get_instance_type_string()
+        inst_type_str = self._get_instance_type_string()
         # shape & dimension names
         dims = ' × '.join(
             [f'{dim[0]} {dim[1]}s'
              for dim in zip(self._data.shape, self._dims)])
         freq_range = f'{self.freqs[0]:0.1f}-{self.freqs[-1]:0.1f} Hz'
-        return f'<{self._data_type} (from {inst_type}) | {dims}, {freq_range}>'
+        return (f'<{self._data_type} '
+                f'(from {inst_type_str}) | {dims}, {freq_range}>')
 
     def _repr_html_(self, caption=None):
         """Build HTML representation of the Spectrum object."""
         from ..html_templates import repr_templates_env
 
-        inst_type = self._get_instance_type_string()
+        inst_type_str = self._get_instance_type_string()
         t = repr_templates_env.get_template('spectrum.html.jinja')
-        t = t.render(spectrum=self, inst_type=inst_type,
+        t = t.render(spectrum=self, inst_type=inst_type_str,
                      data_type=self._data_type)
         return t
 
@@ -309,7 +310,7 @@ def _format_units(self, unit, latex, power=True):
         return f'{pre}{unit}{exp}/{denom}{post}'
 
     def _from_file(self, method, data, freqs, sfreq, shape, dims, data_type,
-                   inst_type, info, metadata=None, drop_log=None,
+                   inst_type_str, info, metadata=None, drop_log=None,
                    event_id=None, events=None, selection=None):
         """Recreate Spectrum object from hdf5 file."""
         from .. import Epochs, Evoked, Info
@@ -324,7 +325,7 @@ def _from_file(self, method, data, freqs, sfreq, shape, dims, data_type,
         self.info = Info(**info)
         self._data_type = data_type
         self.preload = True
-        if inst_type == 'Epochs':
+        if inst_type_str == 'Epochs':
             self._metadata = metadata
             self.drop_log = drop_log
             self.event_id = event_id
@@ -332,7 +333,7 @@ def _from_file(self, method, data, freqs, sfreq, shape, dims, data_type,
             self.selection = selection
         # instance type
         inst_types = dict(Raw=Raw, Epochs=Epochs, Evoked=Evoked)
-        self._inst_type = inst_types[inst_type]
+        self._inst_type = inst_types[inst_type_str]
 
     def _get_instance_type_string(self):
         """Get string representation of the originating instance type."""
@@ -341,15 +342,15 @@ def _get_instance_type_string(self):
 
         parent_classes = self._inst_type.__bases__
         if BaseRaw in parent_classes:
-            inst_type = 'Raw'
+            inst_type_str = 'Raw'
         elif BaseEpochs in parent_classes:
-            inst_type = 'Epochs'
-        elif Evoked in parent_classes:
-            inst_type = 'Evoked'
+            inst_type_str = 'Epochs'
+        elif self._inst_type == Evoked:
+            inst_type_str = 'Evoked'
         else:
             raise RuntimeError(
                 f'Unknown instance type {self._inst_type} in Spectrum')
-        return inst_type
+        return inst_type_str
 
     @property
     def _detrend_picks(self):
@@ -575,7 +576,7 @@ def save(self, fname, *, overwrite=False, verbose=None):
                    shape=self.shape,
                    dims=self._dims,
                    freqs=self.freqs,
-                   inst_type=inst_type_str,
+                   inst_type_str=inst_type_str,
                    data_type=self._data_type,
                    info=self.info)
         if inst_type_str == 'Epochs':
@@ -907,7 +908,7 @@ def read_spectrum(fname):
     defaults = dict(method=None, fmin=None, fmax=None, tmin=None, tmax=None,
                     picks=None, proj=None, reject_by_annotation=None,
                     n_jobs=None, verbose=None)
-    Klass = EpochsSpectrum if hdf5_dict['inst_type'] == 'Epochs' else Spectrum
+    Klass = EpochsSpectrum if hdf5_dict['inst_type_str'] == 'Epochs' else Spectrum
     return Klass(hdf5_dict, **defaults)