diff --git a/src/middlewared/middlewared/plugins/alert.py b/src/middlewared/middlewared/plugins/alert.py
index 368a10cc3f4e..b4104a37203b 100644
--- a/src/middlewared/middlewared/plugins/alert.py
+++ b/src/middlewared/middlewared/plugins/alert.py
@@ -1,7 +1,8 @@
-from collections import defaultdict
+from collections import defaultdict, namedtuple
 from datetime import datetime
 import errno
 import os
+import time
 import traceback
 import uuid
 
@@ -34,6 +35,8 @@
 ALERT_SOURCES = {}
 ALERT_SERVICES_FACTORIES = {}
 
+AlertSourceLock = namedtuple("AlertSourceLock", ["source_name", "expires_at"])
+
 
 class AlertSourceRunFailedAlertClass(AlertClass):
     category = AlertCategory.SYSTEM
@@ -401,6 +404,10 @@ async def __run_alerts(self):
                         if remote_failover_status == "BACKUP":
                             run_on_backup_node = True
 
+        for k, source_lock in list(self.sources_locks.items()):
+            if source_lock.expires_at <= time.monotonic():
+                await self.unblock_source(k)
+
         for alert_source in ALERT_SOURCES.values():
             if not alert_source.schedule.should_run(datetime.utcnow(), self.alert_source_last_run[alert_source.name]):
                 continue
@@ -496,19 +503,19 @@ async def run_source(self, source_name):
             raise CallError("This alert checker is unavailable", CallError.EALERTCHECKERUNAVAILABLE)
 
     @private
-    async def block_source(self, source_name):
+    async def block_source(self, source_name, timeout=3600):
         if source_name not in ALERT_SOURCES:
             raise CallError("Invalid alert source")
 
         lock = str(uuid.uuid4())
         self.blocked_sources[source_name].add(lock)
-        self.sources_locks[lock] = source_name
+        self.sources_locks[lock] = AlertSourceLock(source_name, time.monotonic() + timeout)
         return lock
 
     @private
     async def unblock_source(self, lock):
-        source_name = self.sources_locks.pop(lock)
-        self.blocked_sources[source_name].remove(lock)
+        source_lock = self.sources_locks.pop(lock)
+        self.blocked_sources[source_lock.source_name].remove(lock)
 
     async def __run_source(self, source_name):
         alert_source = ALERT_SOURCES[source_name]