diff --git a/doc/classes/Mutex.xml b/doc/classes/Mutex.xml
index f5f6308401d..336d7f1cf2b 100644
--- a/doc/classes/Mutex.xml
+++ b/doc/classes/Mutex.xml
@@ -15,6 +15,7 @@
 			</return>
 			<description>
 				Locks this [Mutex], blocks until it is unlocked by the current owner.
+				[b]Note:[/b] This function returns without blocking if the thread already has ownership of the mutex.
 			</description>
 		</method>
 		<method name="try_lock">
@@ -22,6 +23,7 @@
 			</return>
 			<description>
 				Tries locking this [Mutex], but does not block. Returns [constant OK] on success, [constant ERR_BUSY] otherwise.
+				[b]Note:[/b] This function returns [constant OK] if the thread already has ownership of the mutex.
 			</description>
 		</method>
 		<method name="unlock">
@@ -29,6 +31,7 @@
 			</return>
 			<description>
 				Unlocks this [Mutex], leaving it to other threads.
+				[b]Note:[/b] If a thread called [method lock] or [method try_lock] multiple times while already having ownership of the mutex, it must also call [method unlock] the same number of times in order to unlock it correctly.
 			</description>
 		</method>
 	</methods>