diff --git a/tests/test_boards.py b/tests/test_boards.py
index c0f34e0..4cc69e1 100644
--- a/tests/test_boards.py
+++ b/tests/test_boards.py
@@ -34,6 +34,7 @@ def setup_function(function):
 
 def teardown_function(function):
     Device._pin_factory.reset()
+    Device._reservations.clear()
 
 def teardown_module(module):
     # make sure we reset the default
diff --git a/tests/test_inputs.py b/tests/test_inputs.py
index faf5894..dbfd7dc 100644
--- a/tests/test_inputs.py
+++ b/tests/test_inputs.py
@@ -18,6 +18,7 @@ from gpiozero import *
 
 def teardown_function(function):
     Device._pin_factory.reset()
+    Device._reservations.clear()
 
 
 def test_input_initial_values():
diff --git a/tests/test_outputs.py b/tests/test_outputs.py
index 3816226..4fbcbf4 100644
--- a/tests/test_outputs.py
+++ b/tests/test_outputs.py
@@ -22,6 +22,7 @@ from gpiozero import *
 
 def teardown_function(function):
     Device._pin_factory.reset()
+    Device._reservations.clear()
 
 
 def test_output_initial_values():