diff --git a/be_example_test.go b/be_example_test.go
index d9d365c..a6e4f08 100644
--- a/be_example_test.go
+++ b/be_example_test.go
@@ -35,10 +35,10 @@ func Example() {
 
 	type mytype string
 	var mystring mytype = "hello, world"
-	be.Match(t, `world`, mystring)               // good
-	be.Match(t, `World`, mystring)               // bad
-	be.Match(t, `^\W*$`, []byte("\a\b\x00\r\t")) // good
-	be.Match(t, `^\W*$`, []byte("\a\bo\r\t"))    // bad
+	be.Match(t, `world`, mystring)                 // good
+	be.Match(t, `World`, mystring)                 // bad
+	be.Match(t, `^\W*$`, []byte("\a\b\x00\r\t"))   // good
+	be.NoMatch(t, `^\W*$`, []byte("\a\b\x00\r\t")) // bad
 
 	seq := strings.FieldsSeq("1 2 3 4")
 	be.EqualLength(t, 4, seq)     // good
@@ -55,8 +55,8 @@ func Example() {
 	// got: <nil>
 	// got errors.Is(<nil>, permission denied) == false
 	// got errors.As((O_o), **fs.PathError) == false
-	// /World/ !~ "hello, world"
-	// /^\W*$/ !~ "\a\bo\r\t"
+	// missing match: /World/ !~ "hello, world"
+	// unexpected match: /^\W*$/ =~ "\a\b\x00\r\t"
 	// want len(seq) == 1; got at least 2
 	// want len(seq) >= 5; got 4
 	// want len(seq) >= 4; got 3
diff --git a/in.go b/in.go
index da4e236..e55da6a 100644
--- a/in.go
+++ b/in.go
@@ -1,35 +1,24 @@
 package be
 
 import (
-	"bytes"
-	"reflect"
-	"strings"
+	"regexp"
 	"testing"
 )
 
 // In calls t.Fatalf if needle is not contained in the string or []byte haystack.
+//
+// Deprecated: Use Match(t, regexp.QuoteMeta(needle), haystack).
+//
+//go:fix inline
 func In[byteseq ~string | ~[]byte](t testing.TB, needle string, haystack byteseq) {
-	t.Helper()
-	if !in(needle, haystack) {
-		t.Fatalf("%q not in %q", needle, haystack)
-	}
+	Match(t, regexp.QuoteMeta(needle), haystack)
 }
 
 // NotIn calls t.Fatalf if needle is contained in the string or []byte haystack.
+//
+// Deprecated: Use NoMatch(t, regexp.QuoteMeta(needle), haystack).
+//
+//go:fix inline
 func NotIn[byteseq ~string | ~[]byte](t testing.TB, needle string, haystack byteseq) {
-	t.Helper()
-	if in(needle, haystack) {
-		t.Fatalf("%q in %q", needle, haystack)
-	}
-}
-
-func in[byteseq ~string | ~[]byte](needle string, haystack byteseq) bool {
-	rv := reflect.ValueOf(haystack)
-	switch rv.Kind() {
-	case reflect.String:
-		return strings.Contains(rv.String(), needle)
-	case reflect.Slice:
-		return bytes.Contains(rv.Bytes(), []byte(needle))
-	}
-	panic("unreachable")
+	NoMatch(t, regexp.QuoteMeta(needle), haystack)
 }
diff --git a/match.go b/match.go
index f4229b3..ad98855 100644
--- a/match.go
+++ b/match.go
@@ -13,7 +13,18 @@ func Match[byteseq ~string | ~[]byte](t testing.TB, pattern string, got byteseq)
 	t.Helper()
 	reg := regexp.MustCompile(pattern)
 	if !match(reg, got) {
-		t.Fatalf("/%s/ !~ %q", pattern, got)
+		t.Fatalf("missing match: /%s/ !~ %q", pattern, got)
+	}
+}
+
+// NoMatch calls t.Fatalf if got matches the [regexp] pattern.
+//
+// The pattern must compile.
+func NoMatch[byteseq ~string | ~[]byte](t testing.TB, pattern string, got byteseq) {
+	t.Helper()
+	reg := regexp.MustCompile(pattern)
+	if match(reg, got) {
+		t.Fatalf("unexpected match: /%s/ =~ %q", pattern, got)
 	}
 }