diff --git a/CHANGELOG.md b/CHANGELOG.md
index ef4bd40f61..9af5342c39 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -84,6 +84,7 @@
 * [BUGFIX] Experimental Alertmanager API: Do not allow empty Alertmanager configurations or bad template filenames to be submitted through the configuration API. #3185
 * [BUGFIX] Reduce failures to update heartbeat when using Consul. #3259
 * [BUGFIX] When using ruler sharding, moving all user rule groups from ruler to a different one and then back could end up with some user groups not being evaluated at all. #3235
+* [BUGFIX] Fixes the metric `cortex_prometheus_rule_group_duration_seconds` in the Ruler, it wouldn't report any values. #3310
 
 ## 1.4.0 / 2020-10-02
 
diff --git a/pkg/ruler/manager_metrics.go b/pkg/ruler/manager_metrics.go
index b888a06571..f4c3942229 100644
--- a/pkg/ruler/manager_metrics.go
+++ b/pkg/ruler/manager_metrics.go
@@ -148,7 +148,7 @@ func (m *ManagerMetrics) Collect(out chan<- prometheus.Metric) {
 	// If same user is later re-added, all metrics will start from 0, which is fine.
 
 	data.SendSumOfSummariesPerUser(out, m.EvalDuration, "prometheus_rule_evaluation_duration_seconds")
-	data.SendSumOfSummariesPerUser(out, m.IterationDuration, "cortex_prometheus_rule_group_duration_seconds")
+	data.SendSumOfSummariesPerUser(out, m.IterationDuration, "prometheus_rule_group_duration_seconds")
 
 	data.SendSumOfCountersPerUser(out, m.IterationsMissed, "prometheus_rule_group_iterations_missed_total")
 	data.SendSumOfCountersPerUser(out, m.IterationsScheduled, "prometheus_rule_group_iterations_total")
diff --git a/pkg/ruler/manager_metrics_test.go b/pkg/ruler/manager_metrics_test.go
index 2686e24235..91149f59da 100644
--- a/pkg/ruler/manager_metrics_test.go
+++ b/pkg/ruler/manager_metrics_test.go
@@ -61,12 +61,27 @@ cortex_prometheus_rule_evaluations_total{rule_group="group_two",user="user2"} 10
 cortex_prometheus_rule_evaluations_total{rule_group="group_two",user="user3"} 100
 # HELP cortex_prometheus_rule_group_duration_seconds The duration of rule group evaluations.
 # TYPE cortex_prometheus_rule_group_duration_seconds summary
-cortex_prometheus_rule_group_duration_seconds_sum{user="user1"} 0
-cortex_prometheus_rule_group_duration_seconds_count{user="user1"} 0
-cortex_prometheus_rule_group_duration_seconds_sum{user="user2"} 0
-cortex_prometheus_rule_group_duration_seconds_count{user="user2"} 0
-cortex_prometheus_rule_group_duration_seconds_sum{user="user3"} 0
-cortex_prometheus_rule_group_duration_seconds_count{user="user3"} 0
+cortex_prometheus_rule_group_duration_seconds{user="user1",quantile="0.01"} 1
+cortex_prometheus_rule_group_duration_seconds{user="user1",quantile="0.05"} 1
+cortex_prometheus_rule_group_duration_seconds{user="user1",quantile="0.5"} 1
+cortex_prometheus_rule_group_duration_seconds{user="user1",quantile="0.9"} 1
+cortex_prometheus_rule_group_duration_seconds{user="user1",quantile="0.99"} 1
+cortex_prometheus_rule_group_duration_seconds_sum{user="user1"} 1
+cortex_prometheus_rule_group_duration_seconds_count{user="user1"} 1
+cortex_prometheus_rule_group_duration_seconds{user="user2",quantile="0.01"} 10
+cortex_prometheus_rule_group_duration_seconds{user="user2",quantile="0.05"} 10
+cortex_prometheus_rule_group_duration_seconds{user="user2",quantile="0.5"} 10
+cortex_prometheus_rule_group_duration_seconds{user="user2",quantile="0.9"} 10
+cortex_prometheus_rule_group_duration_seconds{user="user2",quantile="0.99"} 10
+cortex_prometheus_rule_group_duration_seconds_sum{user="user2"} 10
+cortex_prometheus_rule_group_duration_seconds_count{user="user2"} 1
+cortex_prometheus_rule_group_duration_seconds{user="user3",quantile="0.01"} 100
+cortex_prometheus_rule_group_duration_seconds{user="user3",quantile="0.05"} 100
+cortex_prometheus_rule_group_duration_seconds{user="user3",quantile="0.5"} 100
+cortex_prometheus_rule_group_duration_seconds{user="user3",quantile="0.9"} 100
+cortex_prometheus_rule_group_duration_seconds{user="user3",quantile="0.99"} 100
+cortex_prometheus_rule_group_duration_seconds_sum{user="user3"} 100
+cortex_prometheus_rule_group_duration_seconds_count{user="user3"} 1
 # HELP cortex_prometheus_rule_group_iterations_missed_total The total number of rule group evaluations missed due to slow rule group evaluation.
 # TYPE cortex_prometheus_rule_group_iterations_missed_total counter
 cortex_prometheus_rule_group_iterations_missed_total{user="user1"} 1