diff --git a/epicardium/epicardium.h b/epicardium/epicardium.h
index b87cce5cc794ff43794d58704024b0b2f2d2ff1d..4e52d85c51c38d897f38dbee03ed96cbbb7b0de1 100644
--- a/epicardium/epicardium.h
+++ b/epicardium/epicardium.h
@@ -92,6 +92,7 @@ API(API_LEDS_SET, void epic_leds_set(int led, uint8_t r, uint8_t g, uint8_t b));
  *    - ``-ENODEV``: Sensor is not currently available.
  *    - ``-EBADF``: The given sensor descriptor is unknown.
  *    - ``-EINVAL``:  ``count`` is not a multiple of the sensor's sample size.
+ *    - ``-EBUSY``: The descriptor table lock could not be acquired.
  *
  * **Example**:
  *
diff --git a/epicardium/modules/stream.h b/epicardium/modules/stream.h
index 5bce8d56ed29414a06fdaa90d0b83fbe7a4fca32..32c9e6e219bc7b7998babcd25236d2417d61b8c5 100644
--- a/epicardium/modules/stream.h
+++ b/epicardium/modules/stream.h
@@ -60,6 +60,7 @@ struct stream_info {
  *
  *    - ``-EINVAL``: Out of range sensor descriptor.
  *    - ``-EACCES``: Stream already registered.
+ *    - ``-EBUSY``: The descriptor lock could not be acquired.
  */
 int stream_register(int sd, struct stream_info *stream);
 
@@ -74,6 +75,7 @@ int stream_register(int sd, struct stream_info *stream);
  *
  *    - ``-EINVAL``: Out of range sensor descriptor.
  *    - ``-EACCES``: Stream ``stream`` was not registered for ``sd``.
+ *    - ``-EBUSY``: The descriptor lock could not be acquired.
  */
 int stream_deregister(int sd, struct stream_info *stream);