diff --git a/prettifier.go b/prettifier.go
index 0199965..6994e8f 100644
--- a/prettifier.go
+++ b/prettifier.go
@@ -160,13 +160,21 @@ func appendPrettifiedExpr(dst []byte, e Expr, indent int, needParens bool) []byt
 		lfss := t.labelFilterss
 		offset := 0
 		metricName := getMetricNameFromLabelFilterss(lfss)
+		metricNamehasEscapedChars := hasEscapedChars(metricName)
+
 		if metricName != "" {
 			offset = 1
 		}
 		dst = appendIndent(dst, indent)
-		dst = appendEscapedIdent(dst, metricName)
+		if !metricNamehasEscapedChars {
+			dst = appendEscapedIdent(dst, metricName)
+		}
 		if !isOnlyMetricNameInLabelFilterss(lfss) {
 			dst = append(dst, "{\n"...)
+			if metricNamehasEscapedChars {
+				dst = ifEscapedCharsAppendQuotedIdent(dst, metricName)
+				dst = append(dst, ',', ' ', '\n')
+			}
 			for i, lfs := range lfss {
 				lfs = lfs[offset:]
 				if len(lfs) == 0 {
diff --git a/prettifier_test.go b/prettifier_test.go
index 159606e..dfbb012 100644
--- a/prettifier_test.go
+++ b/prettifier_test.go
@@ -123,6 +123,19 @@ func TestPrettifySuccess(t *testing.T) {
 	another(`process_cpu_seconds_total{foo="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"}`,
 		`process_cpu_seconds_total{
   foo="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"
+}`)
+	another(`process_cpu_seconds_total{"3foo"="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"}`,
+		`process_cpu_seconds_total{
+  "3foo"="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"
+}`)
+	another(`{"process_cpu_seconds_total", "foo"="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"}`,
+		`process_cpu_seconds_total{
+  foo="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"
+}`)
+	another(`{"3process_cpu_seconds_total", "foo"="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"}`,
+		`{
+"3process_cpu_seconds_total", 
+  foo="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk"
 }`)
 	another(`process_cpu_seconds_total{foo="bar",xjljljlkjopiwererrewre="asdfdsfdsfsdfdsfjkljlk",very_long_label_aaaaaaaaaaaaaaa="fdsfdsffdsfs"}`,
 		`process_cpu_seconds_total{