diff --git a/docs/environment_files/environment.yml b/docs/environment_files/environment.yml
index a4461795..9c399688 100644
--- a/docs/environment_files/environment.yml
+++ b/docs/environment_files/environment.yml
@@ -35,6 +35,7 @@ dependencies:
     - scipy                           # Scientific python package
     - sparselt>=0.1.3                 # Regridding earth system model data
     - tabulate                        # Pretty-printing for column data
+    - tk                              # Tcl/Tk interface
     - xarray                          # Read data from netCDF etc files
     #
     # NOTE: These packages need to be pegged at specific versions
diff --git a/gcpy/examples/plotting/plot_comparisons.py b/gcpy/examples/plotting/plot_comparisons.py
index 1ee318db..649b04b7 100755
--- a/gcpy/examples/plotting/plot_comparisons.py
+++ b/gcpy/examples/plotting/plot_comparisons.py
@@ -15,7 +15,7 @@
 import argparse
 import xarray as xr
 from matplotlib import use as mpl_use
-mpl_use("TkAgg")                          # X11 backend for plt.show()
+#mpl_use("TkAgg")                          # X11 backend for plt.show()
 import matplotlib.pyplot as plt
 from gcpy import plot
 from gcpy.constants import skip_these_vars
diff --git a/gcpy/examples/plotting/plot_single_panel.py b/gcpy/examples/plotting/plot_single_panel.py
index a66af652..1980ef12 100755
--- a/gcpy/examples/plotting/plot_single_panel.py
+++ b/gcpy/examples/plotting/plot_single_panel.py
@@ -16,7 +16,7 @@
 import argparse
 import xarray as xr
 from matplotlib import use as mpl_use
-mpl_use("TkAgg")                        # X11 backend for plt.show()
+#mpl_use("TkAgg")                        # X11 backend for plt.show()
 import matplotlib.pyplot as plt
 from gcpy import plot
 from gcpy.util import rename_and_flip_gchp_rst_vars