diff --git a/juju/utils.py b/juju/utils.py
index <HASH>..<HASH> 100644
--- a/juju/utils.py
+++ b/juju/utils.py
@@ -115,6 +115,8 @@ class IdQueue:
 
 async def block_until(*conditions, timeout=None, wait_period=0.5):
     """Return only after all conditions are true.
+    If a timeout occurs, it cancels the task and raises 
+    asyncio.TimeoutError.
 
     """
     async def _block():
@@ -125,7 +127,8 @@ async def block_until(*conditions, timeout=None, wait_period=0.5):
 
 async def block_until_with_coroutine(condition_coroutine, timeout=None, wait_period=0.5):
     """Return only after the given coroutine returns True.
-
+    If a timeout occurs, it cancels the task and raises 
+    asyncio.TimeoutError.
     """
     async def _block():
         while not await condition_coroutine():
Minor comments on docs for block_until related functions.