diff --git a/ensemble_md/analysis/analyze_traj.py b/ensemble_md/analysis/analyze_traj.py
index 3e448fd9..9c7de5c1 100644
--- a/ensemble_md/analysis/analyze_traj.py
+++ b/ensemble_md/analysis/analyze_traj.py
@@ -694,7 +694,8 @@ def plot_transit_time(trajs, N, fig_prefix=None, dt=None, folder='.'):
                 t_k0 = list(np.array(t_k0) * dt)  # units: ps
                 t_roundtrip = list(np.array(t_roundtrip) * dt)  # units: ps
                 if len(t_0k) + len(t_k0) + len(t_roundtrip) > 0:  # i.e. not all are empty
-                    if np.max([t_0k, t_k0, t_roundtrip]) > t_max:
+                    
+                    if np.max(list(chain.from_iterable([t_0k, t_k0, t_roundtrip]))) > t_max:
                         t_max = np.max([t_0k, t_k0, t_roundtrip])
 
                     if t_max >= 10000:
@@ -745,8 +746,7 @@ def plot_transit_time(trajs, N, fig_prefix=None, dt=None, folder='.'):
             for i in range(len(t_list)):    # t_list[i] is the list for trajectory i
                 plt.plot(np.arange(len(t_list[i])) + 1, t_list[i], label=f'Trajectory {i}', marker=marker)
 
-            flattened_t_list = list(chain.from_iterable(t_list))
-            if np.max(flattened_t_list) >= 10000:
+            if np.max(list(chain.from_iterable(t_list))) >= 10000:
                 plt.ticklabel_format(style='sci', axis='y', scilimits=(0, 0))
             plt.xlabel('Event index')
             plt.ylabel(f'{y_labels[t]}')
diff --git a/ensemble_md/tests/test_analyze_traj.py b/ensemble_md/tests/test_analyze_traj.py
index 5f615178..cd3f29dc 100644
--- a/ensemble_md/tests/test_analyze_traj.py
+++ b/ensemble_md/tests/test_analyze_traj.py
@@ -528,8 +528,38 @@ def test_plot_transit_time(mock_plt):
     mock_plt.savefig.assert_not_called()
 
 
-def test_plot_g_vecs():
-    pass
+@patch('ensemble_md.analysis.analyze_traj.plt')
+def test_plot_g_vecs(mock_plt):
+    cmap = mock_plt.cm.ocean
+    mock_ax = MagicMock()
+    mock_plt.gca.return_value = mock_ax
+    
+    # Case 1: Short g_vecs with refs and with plot_rmse = True
+    g_vecs = np.array([[0, 10, 20, 30], [0, 8, 18, 28]])
+    refs = np.array([0, 8, 18, 28])
+    refs_err = np.array([0.1, 0.1, 0.1, 0.1])
+
+    analyze_traj.plot_g_vecs(g_vecs, refs, refs_err, plot_rmse=True)
+
+    mock_plt.figure.assert_called()
+    mock_plt.plot.assert_called()
+    mock_plt.xlabel.assert_called_with('Iteration index')
+    # mock_plt.ylabel.assert_called_any('Alchemical weight (kT)')
+    mock_plt.xlim.assert_called()
+    mock_plt.grid.assert_called()
+    mock_plt.legend.assert_called_with(loc='center left', bbox_to_anchor=(1, 0.2))
+
+    assert mock_plt.figure.call_count == 2
+    assert mock_plt.plot.call_count == 4
+    assert mock_plt.axhline.call_count == 3
+    assert mock_plt.fill_between.call_count == 3
+    assert mock_plt.grid.call_count == 2
+
+    assert mock_plt.ylabel.call_args_list[0][0] == ('Alchemical weight (kT)',)
+    assert mock_plt.ylabel.call_args_list[1][0] == ('RMSE in the alchemical weights (kT)',)
+
+
+    # Case 2: Long g_vecs
 
 
 def test_get_swaps():