diff --git a/archetypal/utils.py b/archetypal/utils.py
index 6ec1810a..dae35245 100644
--- a/archetypal/utils.py
+++ b/archetypal/utils.py
@@ -20,7 +20,6 @@
 
 import numpy as np
 import pandas as pd
-from pandas.io.json import json_normalize
 from path import Path
 from tqdm.auto import tqdm
 
@@ -366,7 +365,7 @@ def load_umi_template(json_template):
         with open(json_template) as f:
             dicts = json.load(f, object_pairs_hook=OrderedDict)
 
-            return [{key: json_normalize(value)} for key, value in dicts.items()]
+            return [{key: pd.json_normalize(value)} for key, value in dicts.items()]
     else:
         raise ValueError("File {} does not exist".format(json_template))
 
diff --git a/archetypal/zone_graph.py b/archetypal/zone_graph.py
index 71b31950..0ab3a00c 100644
--- a/archetypal/zone_graph.py
+++ b/archetypal/zone_graph.py
@@ -459,7 +459,7 @@ def plot_graph2d(
             G = networkx.convert_node_labels_to_integers(G, label_attribute="name")
         tree = networkx.dfs_tree(G)
         pos = layout_function(tree, *func_args)
-        with plt.style.context((plt_style)):
+        with plt.style.context(plt_style):
             if ax:
                 fig = plt.gcf()
             else:
diff --git a/requirements.txt b/requirements.txt
index 9d28c85f..6743e5b7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,8 +2,8 @@ networkx~=2.6.1
 eppy==0.5.60  # for stability
 matplotlib~=3.4  # because of TwoSlopesNorm
 pycountry~=20.7.3
-scikit-learn~=1.0.2
-pandas>=1.2.0,<2.0
+scikit-learn
+pandas>=2.0.3
 numpy>=1.17
 tqdm
 tabulate~=0.8.9
@@ -20,4 +20,4 @@ energy-pandas
 validator_collection
 pint<=0.19
 typing_extensions
-pydantic-settings
\ No newline at end of file
+pydantic-settings
diff --git a/tests/test_zonegraph.py b/tests/test_zonegraph.py
index a6db9e3d..b6ba89b9 100644
--- a/tests/test_zonegraph.py
+++ b/tests/test_zonegraph.py
@@ -88,7 +88,7 @@ def test_viewgraph2d(self, G):
             font_size=8,
             color_nodes="core",
             node_labels_to_integers=True,
-            plt_style="seaborn",
+            plt_style="ggplot",
             save=False,
             show=False,
             filename="test",