diff --git a/internal/integration/all_of_test.go b/internal/integration/all_of_test.go
index 083ab59ae..907974b0b 100644
--- a/internal/integration/all_of_test.go
+++ b/internal/integration/all_of_test.go
@@ -2,6 +2,7 @@ package integration
 
 import (
 	"context"
+	"fmt"
 	"net/http/httptest"
 	"strings"
 	"testing"
@@ -50,15 +51,27 @@ func TestAllof(t *testing.T) {
 		require.NoError(t, err)
 	}
 
+	regexPattern := "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
+
 	ctx := context.Background()
 	t.Run("nullableStrings", func(t *testing.T) {
 		err := client.NullableStrings(ctx, api.NilString{})
-		_, ok := errors.Into[*validate.NoRegexMatchError](err)
+		regexMatchErr, ok := errors.Into[*validate.NoRegexMatchError](err)
 		require.True(t, ok, "validate: string: no regex match")
+		require.ErrorContains(
+			t,
+			regexMatchErr,
+			fmt.Sprintf("no regex match: %s", regexPattern),
+		)
 
 		err = client.NullableStrings(ctx, api.NewNilString("foo"))
-		_, ok = errors.Into[*validate.NoRegexMatchError](err)
+		regexMatchErr, ok = errors.Into[*validate.NoRegexMatchError](err)
 		require.True(t, ok, "validate: string: no regex match")
+		require.ErrorContains(
+			t,
+			regexMatchErr,
+			fmt.Sprintf("no regex match: %s", regexPattern),
+		)
 
 		err = client.NullableStrings(ctx, api.NewNilString("127.0.0.1"))
 		require.NoError(t, err)
diff --git a/validate/errors.go b/validate/errors.go
index 7d6d7c595..42240b693 100644
--- a/validate/errors.go
+++ b/validate/errors.go
@@ -2,6 +2,7 @@ package validate
 
 import (
 	"fmt"
+	"github.com/ogen-go/ogen/ogenregex"
 	"strings"
 
 	"github.com/go-faster/errors"
@@ -102,9 +103,11 @@ func (e *MaxLengthError) Error() string {
 }
 
 // NoRegexMatchError reports that value have no regexp match.
-type NoRegexMatchError struct{}
+type NoRegexMatchError struct {
+	Pattern ogenregex.Regexp
+}
 
 // MaxLengthError implements error.
-func (*NoRegexMatchError) Error() string {
-	return "no regex match"
+func (e *NoRegexMatchError) Error() string {
+	return fmt.Sprintf("no regex match: %s", e.Pattern.String())
 }
diff --git a/validate/string.go b/validate/string.go
index 5314b5602..1ecf3f617 100644
--- a/validate/string.go
+++ b/validate/string.go
@@ -124,7 +124,9 @@ func (t String) Validate(v string) error {
 			return errors.Wrap(err, "execute regex")
 		}
 		if !match {
-			return &NoRegexMatchError{}
+			return &NoRegexMatchError{
+				Pattern: r,
+			}
 		}
 	}
 	return nil