diff --git a/src/calibre/devices/interface.py b/src/calibre/devices/interface.py
index 3fa9698615..de11a19542 100644
--- a/src/calibre/devices/interface.py
+++ b/src/calibre/devices/interface.py
@@ -92,7 +92,7 @@ class DevicePlugin(Plugin):
     #: A driver with this set to true is responsible for detection of devices,
     #: managing a blacklist of devices, a list of ejected devices and so forth.
     #: calibre will periodically call the detect_managed_devices() method and
-    #: is it returns a detected device, calibre will call open(). open() will
+    #: if it returns a detected device, calibre will call open(). open() will
     #: be called every time a device is returned even is previous calls to open()
     #: failed, therefore the driver must maintain its own blacklist of failed
     #: devices. Similarly, when ejecting, calibre will call eject() and then