diff --git a/tests/__init__.py b/tests/__init__.py
index e69de29..c21d758 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -0,0 +1,8 @@
+import warnings
+
+import matplotlib.pyplot as plt
+
+# switch matplotlib backend to non-Gui, preventing plots being displayed
+plt.switch_backend("Agg")
+# suppress UserWarning that the current backend cannot show plots
+warnings.filterwarnings("ignore", "Matplotlib is currently using agg")