diff --git a/lib/promscrape/targets_response.qtpl b/lib/promscrape/targets_response.qtpl
index 448012c73..72a445f91 100644
--- a/lib/promscrape/targets_response.qtpl
+++ b/lib/promscrape/targets_response.qtpl
@@ -116,9 +116,12 @@ job={%q= jobName %} (0/0 up)
 {% endfunc %}
 
 {% func formatLabel(labels []prompbmarshal.Label) %}
-{% for _, label := range labels %}
-    {%s label.Name %}={%q label.Value %} {% space %}
-{% endfor %}
+{
+  {% for i, label := range labels %}
+      {%s label.Name %}={%q label.Value %}
+      {% if i+1 < len(labels) %},{% endif %}
+  {% endfor %}
+}
 {% endfunc %}
 
 {% endstripspace %}
diff --git a/lib/promscrape/targets_response.qtpl.go b/lib/promscrape/targets_response.qtpl.go
index 334d1873f..1a2015e24 100644
--- a/lib/promscrape/targets_response.qtpl.go
+++ b/lib/promscrape/targets_response.qtpl.go
@@ -359,43 +359,51 @@ func TargetsResponseHTML(jts []jobTargetsStatuses, emptyJobs []string, redirectP
 
 //line lib/promscrape/targets_response.qtpl:118
 func streamformatLabel(qw422016 *qt422016.Writer, labels []prompbmarshal.Label) {
-//line lib/promscrape/targets_response.qtpl:119
-	for _, label := range labels {
+//line lib/promscrape/targets_response.qtpl:118
+	qw422016.N().S(`{`)
 //line lib/promscrape/targets_response.qtpl:120
-		qw422016.E().S(label.Name)
-//line lib/promscrape/targets_response.qtpl:120
-		qw422016.N().S(`=`)
-//line lib/promscrape/targets_response.qtpl:120
-		qw422016.E().Q(label.Value)
-//line lib/promscrape/targets_response.qtpl:120
-		qw422016.N().S(` `)
+	for i, label := range labels {
 //line lib/promscrape/targets_response.qtpl:121
+		qw422016.E().S(label.Name)
+//line lib/promscrape/targets_response.qtpl:121
+		qw422016.N().S(`=`)
+//line lib/promscrape/targets_response.qtpl:121
+		qw422016.E().Q(label.Value)
+//line lib/promscrape/targets_response.qtpl:122
+		if i+1 < len(labels) {
+//line lib/promscrape/targets_response.qtpl:122
+			qw422016.N().S(`,`)
+//line lib/promscrape/targets_response.qtpl:122
+		}
+//line lib/promscrape/targets_response.qtpl:123
 	}
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:123
+	qw422016.N().S(`}`)
+//line lib/promscrape/targets_response.qtpl:125
 }
 
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 func writeformatLabel(qq422016 qtio422016.Writer, labels []prompbmarshal.Label) {
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	qw422016 := qt422016.AcquireWriter(qq422016)
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	streamformatLabel(qw422016, labels)
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	qt422016.ReleaseWriter(qw422016)
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 }
 
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 func formatLabel(labels []prompbmarshal.Label) string {
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	qb422016 := qt422016.AcquireByteBuffer()
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	writeformatLabel(qb422016, labels)
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	qs422016 := string(qb422016.B)
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	qt422016.ReleaseByteBuffer(qb422016)
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 	return qs422016
-//line lib/promscrape/targets_response.qtpl:122
+//line lib/promscrape/targets_response.qtpl:125
 }