diff --git a/bob/bio/face/algorithm/GaborJet.py b/bob/bio/face/algorithm/GaborJet.py
index a878819f1f53f78cc60a8ba48bedde34a6a1dd59..54879038e63d6171a80bf53887958191d87f1463 100644
--- a/bob/bio/face/algorithm/GaborJet.py
+++ b/bob/bio/face/algorithm/GaborJet.py
@@ -11,6 +11,7 @@ import math
 from bob.bio.base.algorithm import Algorithm
 from bob.bio.face.extractor import GridGraph
 
+
 class GaborJet(Algorithm):
     """Computes a comparison of lists of Gabor jets using a similarity function of :py:class:`bob.ip.gabor.Similarity`.
 
@@ -72,21 +73,20 @@ class GaborJet(Algorithm):
             multiple_probe_scoring=None,
         )
 
-        self.gabor_jet_similarity_type=gabor_jet_similarity_type
-        self.multiple_feature_scoring=multiple_feature_scoring
-        self.gabor_directions=gabor_directions
-        self.gabor_scales=gabor_scales
-        self.gabor_sigma=gabor_sigma
-        self.gabor_maximum_frequency=gabor_maximum_frequency
-        self.gabor_frequency_step=gabor_frequency_step
-        self.gabor_power_of_k=gabor_power_of_k
-        self.gabor_dc_free=gabor_dc_free
+        self.gabor_jet_similarity_type = gabor_jet_similarity_type
+        self.multiple_feature_scoring = multiple_feature_scoring
+        self.gabor_directions = gabor_directions
+        self.gabor_scales = gabor_scales
+        self.gabor_sigma = gabor_sigma
+        self.gabor_maximum_frequency = gabor_maximum_frequency
+        self.gabor_frequency_step = gabor_frequency_step
+        self.gabor_power_of_k = gabor_power_of_k
+        self.gabor_dc_free = gabor_dc_free
 
         self.gabor_jet_similarity_type = gabor_jet_similarity_type
 
         self._init_non_pickables()
 
-
     def _init_non_pickables(self):
         # the Gabor wavelet transform; used by (some of) the Gabor jet similarities
         self.gwt = bob.ip.gabor.Transform(
@@ -128,9 +128,10 @@ class GaborJet(Algorithm):
         }[self.multiple_feature_scoring]
 
     def _check_feature(self, feature):
-        # import ipdb; ipdb.set_trace()
+
         assert isinstance(feature, list) or isinstance(feature, numpy.ndarray)
         assert len(feature)
+        feature = GridGraph.serialize_jets(feature)
         assert all(isinstance(f, bob.ip.gabor.Jet) for f in feature)
 
     def enroll(self, enroll_features):
@@ -215,7 +216,7 @@ class GaborJet(Algorithm):
         model = []
         for g in range(count):
             name = "Node-" + str(g + 1)
-            f.cd(name)            
+            f.cd(name)
             model.append(GridGraph.serialize_jets(bob.ip.gabor.load_jets(f)))
             f.cd("..")
         return model
@@ -354,4 +355,3 @@ class GaborJet(Algorithm):
     def __setstate__(self, d):
         self.__dict__ = d
         self._init_non_pickables()
-
diff --git a/bob/bio/face/extractor/GridGraph.py b/bob/bio/face/extractor/GridGraph.py
index 89e8e5dc14b56cc9fc55b97ff8bf5b92c9df4118..a3b6e24807f60a9cfed7ed9e847a925f7950be31 100644
--- a/bob/bio/face/extractor/GridGraph.py
+++ b/bob/bio/face/extractor/GridGraph.py
@@ -140,7 +140,7 @@ class GridGraph(Extractor):
                     "Please specify either 'eyes' or the grid parameters 'node_distance' (and 'first_node')!"
                 )
             self._aligned_graph = None
-            self._last_image_resolution = None            
+            self._last_image_resolution = None
             if isinstance(self.node_distance, (int, float)):
                 self.node_distance = (int(self.node_distance), int(self.node_distance))
 
@@ -229,7 +229,7 @@ class GridGraph(Extractor):
             [j.normalize() for j in jets]
 
         # return the extracted face graph
-        return jets
+        return self.__class__.serialize_jets(jets)
 
     def write_feature(self, feature, feature_file):
         """Writes the feature extracted by the `__call__` function to the given file.
@@ -264,7 +264,9 @@ class GridGraph(Extractor):
     feature : [:py:class:`bob.ip.gabor.Jet`]
       The list of Gabor jets read from file.
     """
-        return self.__class__.serialize_jets(bob.ip.gabor.load_jets(bob.io.base.HDF5File(feature_file)))
+        return self.__class__.serialize_jets(
+            bob.ip.gabor.load_jets(bob.io.base.HDF5File(feature_file))
+        )
 
     # re-define the train function to get it non-documented
     def train(*args, **kwargs):
@@ -277,7 +279,7 @@ class GridGraph(Extractor):
 
     def __getstate__(self):
         d = dict(self.__dict__)
-        d.pop("gwt")        
+        d.pop("gwt")
         d.pop("_aligned_graph")
         if "_graph" in d:
             d.pop("_graph")
@@ -287,12 +289,11 @@ class GridGraph(Extractor):
         self.__dict__ = d
         self._init_non_pickables()
 
-
     @staticmethod
     def serialize_jets(jets):
-        serialize_jets = []        
+        serialize_jets = []
         for jet in jets:
             sj = bob.ip.gabor.Jet(jet.length)
             sj.jet = jet.jet
-            serialize_jets.append(sj)            
+            serialize_jets.append(sj)
         return serialize_jets