diff --git a/metricbeat/module/prometheus/collector/collector_test.go b/metricbeat/module/prometheus/collector/collector_test.go
index ef52c114fe1..362ae0a137b 100644
--- a/metricbeat/module/prometheus/collector/collector_test.go
+++ b/metricbeat/module/prometheus/collector/collector_test.go
@@ -120,7 +120,7 @@ func TestGetPromEventsFromMetricFamily(t *testing.T) {
 						"http_request_duration_microseconds": float64(10),
 					},
 					labels: common.MapStr{
-						"quantile": float64(0.99),
+						"quantile": "0.99",
 					},
 				},
 			},
@@ -157,7 +157,7 @@ func TestGetPromEventsFromMetricFamily(t *testing.T) {
 					data: common.MapStr{
 						"http_request_duration_microseconds": uint64(10),
 					},
-					labels: common.MapStr{"le": float64(0.99)},
+					labels: common.MapStr{"le": "0.99"},
 				},
 			},
 		},
diff --git a/metricbeat/module/prometheus/collector/data.go b/metricbeat/module/prometheus/collector/data.go
index 3073d2a03c0..0120aa55db3 100644
--- a/metricbeat/module/prometheus/collector/data.go
+++ b/metricbeat/module/prometheus/collector/data.go
@@ -19,6 +19,7 @@ package collector
 
 import (
 	"math"
+	"strconv"
 
 	"github.com/elastic/beats/libbeat/common"
 
@@ -88,7 +89,7 @@ func getPromEventsFromMetricFamily(mf *dto.MetricFamily) []PromEvent {
 				}
 
 				quantileLabels := labels.Clone()
-				quantileLabels["quantile"] = quantile.GetQuantile()
+				quantileLabels["quantile"] = strconv.FormatFloat(quantile.GetQuantile(), 'f', -1, 64)
 				events = append(events, PromEvent{
 					data: common.MapStr{
 						name: quantile.GetValue(),
@@ -110,8 +111,7 @@ func getPromEventsFromMetricFamily(mf *dto.MetricFamily) []PromEvent {
 
 			for _, bucket := range histogram.GetBucket() {
 				bucketLabels := labels.Clone()
-				// XXX 0 == +Inf?
-				bucketLabels["le"] = bucket.GetUpperBound()
+				bucketLabels["le"] = strconv.FormatFloat(bucket.GetUpperBound(), 'f', -1, 64)
 
 				events = append(events, PromEvent{
 					data: common.MapStr{