diff --git a/rules/manager.go b/rules/manager.go
index b3a60c828..b1002339a 100644
--- a/rules/manager.go
+++ b/rules/manager.go
@@ -1109,9 +1109,6 @@ func (m *Manager) Rules() []Rule {
 
 // AlertingRules returns the list of the manager's alerting rules.
 func (m *Manager) AlertingRules() []*AlertingRule {
-	m.mtx.RLock()
-	defer m.mtx.RUnlock()
-
 	alerts := []*AlertingRule{}
 	for _, rule := range m.Rules() {
 		if alertingRule, ok := rule.(*AlertingRule); ok {