diff --git a/README.rst b/README.rst
index facb330..da9b7dc 100644
--- a/README.rst
+++ b/README.rst
@@ -83,9 +83,12 @@ Usage Example
 
     spi = bitbangio.SPI(SCLK_PIN, MOSI=MOSI_PIN, MISO=MISO_PIN)
     cs.value = 0
+    while not spi.try_lock():
+        pass
     spi.write([0xD0])
     data = [0x00]
     spi.readinto(data)
+    spi.unlock()
     cs.value = 1
     print("Result is {}".format(data))
 
diff --git a/examples/bitbangio_simpletest.py b/examples/bitbangio_simpletest.py
index 824ea05..f394af6 100644
--- a/examples/bitbangio_simpletest.py
+++ b/examples/bitbangio_simpletest.py
@@ -19,8 +19,11 @@
 
 spi = bitbangio.SPI(SCLK_PIN, MOSI=MOSI_PIN, MISO=MISO_PIN)
 cs.value = 0
+while not spi.try_lock():
+    pass
 spi.write([0xD0])
 data = [0x00]
 spi.readinto(data)
+spi.unlock()
 cs.value = 1
 print("Result is {}".format(data))