diff --git a/examples/test_for_leaks.py b/examples/test_for_leaks.py
new file mode 100644
index 0000000..d05a381
--- /dev/null
+++ b/examples/test_for_leaks.py
@@ -0,0 +1,71 @@
+# SPDX-FileCopyrightText: Copyright (c) 2021 Randall Bohn
+#
+# SPDX-License-Identifier: MIT
+"Test displayio_guage.py -- In certain conditions the fill color was leaking out."
+import math
+import random
+import time
+from adafruit_funhouse import FunHouse
+from displayio_gauge import Gauge
+
+funhouse = FunHouse()
+display = funhouse.display
+top_group = funhouse.splash
+display.show(top_group)
+
+color_pass = 0x009900
+color_fail = 0x990000
+
+def make_gauge(radius, thickness):
+    return Gauge(x=display.width//2,y=display.height//2,
+        radius=radius, thickness=thickness, level=10,
+        outline_color=0xEEEEEE,
+        foreground_color=0xFFCC00,
+        background_color=0x3333FF)
+
+# pylint: disable=W0212
+# test access to gauge._bitmap
+def check(gauge):
+    bitmap = gauge._bitmap
+    top_left = (1,1)
+    top_right = (bitmap.width-1,1)
+    bottom_center = (bitmap.width//2, bitmap.height-1)
+    if bitmap[top_left[0],top_left[1]] != 0:
+        raise ValueError("leak detected top_left")
+    if bitmap[top_right[0], top_right[1]] != 0:
+        raise ValueError("leak detected top_right")
+    if bitmap[bottom_center[0], bottom_center[1]] != 0:
+        raise ValueError("leak detected bottom_center")
+
+
+def find_leaks(gauge):
+    for x in range(360*3.0):
+        theta = math.radians(x)
+        level = int(abs(math.sin(theta) * 100))
+        gauge.level = level
+        check(gauge)
+
+
+
+for iteration in range(5):
+    my_radius = random.randrange(10,90)
+    my_thickness = int(min(
+        max(my_radius*0.2, my_radius*random.random()),my_radius*0.85))
+    print(f"iteration={iteration} radius={my_radius} thickness={my_thickness}")
+    my_gauge = make_gauge(my_radius, my_thickness)
+    top_group[0] = my_gauge
+    try:
+        find_leaks(my_gauge)
+        my_gauge.background_color=color_pass
+        time.sleep(3)
+    except ValueError:
+        my_gauge.background_color=color_fail
+        break
+
+if my_gauge.background_color == color_pass:
+    print("PASS!")
+else:
+    print(f"FAIL: Leak detected in iteration {iteration} level={my_gauge.level}.")
+
+while True:
+    time.sleep(1)