diff --git a/pkg/textparse/lex.l b/pkg/textparse/lex.l
index 50d5390a7..f0342d4d9 100644
--- a/pkg/textparse/lex.l
+++ b/pkg/textparse/lex.l
@@ -81,9 +81,9 @@ M     [a-zA-Z_:]
 <lstateLName>{S}({L}|{D})*=           s = lstateLValue
                                       l.offsets = append(l.offsets, l.i-1)
 
-<lstateLValue>\"(\\.|[^\\"])*\"       s = lstateLabels
+<lstateLValue>\"(\\.|[^\\"]|\0)*\"    s = lstateLabels
                                       l.offsets = append(l.offsets, l.i-1)
-<lstateLValue>\'(\\.|[^\\'])*\'       s = lstateLabels
+<lstateLValue>\'(\\.|[^\\']|\0)*\'    s = lstateLabels
                                       l.offsets = append(l.offsets, l.i-1)
 
 <lstateValue>[ \t]+                   l.vstart = l.i
diff --git a/pkg/textparse/lex.l.go b/pkg/textparse/lex.l.go
index d28a0248a..4742c20d8 100644
--- a/pkg/textparse/lex.l.go
+++ b/pkg/textparse/lex.l.go
@@ -318,13 +318,11 @@ yystate27:
 	c = l.next()
 	switch {
 	default:
-		goto yyabort
+		goto yystate27 // c >= '\x00' && c <= '!' || c >= '#' && c <= '[' || c >= ']' && c <= 'ÿ'
 	case c == '"':
 		goto yystate28
 	case c == '\\':
 		goto yystate29
-	case c >= '\x01' && c <= '!' || c >= '#' && c <= '[' || c >= ']' && c <= 'ÿ':
-		goto yystate27
 	}
 
 yystate28:
@@ -344,13 +342,11 @@ yystate30:
 	c = l.next()
 	switch {
 	default:
-		goto yyabort
+		goto yystate30 // c >= '\x00' && c <= '&' || c >= '(' && c <= '[' || c >= ']' && c <= 'ÿ'
 	case c == '\'':
 		goto yystate31
 	case c == '\\':
 		goto yystate32
-	case c >= '\x01' && c <= '&' || c >= '(' && c <= '[' || c >= ']' && c <= 'ÿ':
-		goto yystate30
 	}
 
 yystate31:
@@ -414,13 +410,13 @@ yyrule9: // {S}({L}|{D})*=
 		l.offsets = append(l.offsets, l.i-1)
 		goto yystate0
 	}
-yyrule10: // \"(\\.|[^\\"])*\"
+yyrule10: // \"(\\.|[^\\"]|\0)*\"
 	{
 		s = lstateLabels
 		l.offsets = append(l.offsets, l.i-1)
 		goto yystate0
 	}
-yyrule11: // \'(\\.|[^\\'])*\'
+yyrule11: // \'(\\.|[^\\']|\0)*\'
 	{
 		s = lstateLabels
 		l.offsets = append(l.offsets, l.i-1)
diff --git a/pkg/textparse/parse_test.go b/pkg/textparse/parse_test.go
index 30464d537..52284d282 100644
--- a/pkg/textparse/parse_test.go
+++ b/pkg/textparse/parse_test.go
@@ -38,6 +38,7 @@ some:aggregate:rate5m{a_b="c"}	1
 # HELP go_goroutines Number of goroutines that currently exist.
 # TYPE go_goroutines gauge
 go_goroutines 33  	123123`
+	input += "\nnull_byte_metric{a=\"abc\x00\"} 1"
 
 	int64p := func(x int64) *int64 { return &x }
 
@@ -72,6 +73,10 @@ go_goroutines 33  	123123`
 			v:    33,
 			t:    int64p(123123),
 			lset: labels.FromStrings("__name__", "go_goroutines"),
+		}, {
+			m:    "null_byte_metric{a=\"abc\x00\"}",
+			v:    1,
+			lset: labels.FromStrings("__name__", "null_byte_metric", "a", "abc\x00"),
 		},
 	}