diff --git a/tests/test_plots.py b/tests/test_plots.py
index bd921bb..f326172 100644
--- a/tests/test_plots.py
+++ b/tests/test_plots.py
@@ -1,6 +1,6 @@
 import matplotlib as mpl
 from pandas import Series
-from spei.plot import monthly_density
+from spei.plot import heatmap, monthly_density
 from spei.plot import si as plot_si
 
 mpl.use("Agg")  # prevent _tkinter.TclError: Can't find a usable tk.tcl error
@@ -16,3 +16,7 @@ def test_plot_si_no_background(si: Series) -> None:
 
 def test_plot_monthly_density(si: Series) -> None:
     _ = monthly_density(si, years=[2011], months=[1, 2, 3, 4, 5])
+
+
+def test_plot_heatmap(si: Series) -> None:
+    _ = heatmap([si], cmap="vik", vmin=-3.0, vmax=3.0)