diff --git a/cmd/ogen/main.go b/cmd/ogen/main.go
index 009b149bf..7c5d08231 100644
--- a/cmd/ogen/main.go
+++ b/cmd/ogen/main.go
@@ -114,6 +114,7 @@ func run() error {
 	if flag.NArg() == 0 || specPath == "" {
 		return errors.New("no spec provided")
 	}
+	specPath = filepath.Clean(specPath)
 
 	switch files, err := os.ReadDir(*targetDir); {
 	case os.IsNotExist(err):
@@ -138,6 +139,7 @@ func run() error {
 		_ = logger.Sync()
 	}()
 
+	_, fileName := filepath.Split(specPath)
 	opts := gen.Options{
 		NoClient:             *noClient,
 		NoServer:             *noServer,
@@ -146,6 +148,7 @@ func run() error {
 		SkipUnimplemented:    *skipUnimplemented,
 		InferSchemaType:      *inferTypes,
 		AllowRemote:          *allowRemote,
+		Filename:             fileName,
 		Filters: gen.Filters{
 			PathRegex: filterPath,
 			Methods:   filterMethods,
diff --git a/gen/generator.go b/gen/generator.go
index d2841555c..c58f40a8e 100644
--- a/gen/generator.go
+++ b/gen/generator.go
@@ -49,6 +49,10 @@ type Options struct {
 	AllowRemote bool
 	// Remote is remote reference resolver options.
 	Remote RemoteOptions
+	// Filename is a name of the spec file.
+	//
+	// Used for error messages.
+	Filename string
 	// Filters contains filters to skip operations.
 	Filters Filters
 	// IgnoreNotImplemented contains ErrNotImplemented messages to ignore.
@@ -98,6 +102,7 @@ func NewGenerator(spec *ogen.Spec, opts Options) (*Generator, error) {
 	}
 	api, err := parser.Parse(spec, parser.Settings{
 		External:   external,
+		Filename:   opts.Filename,
 		InferTypes: opts.InferSchemaType,
 	})
 	if err != nil {
diff --git a/gen_test.go b/gen_test.go
index 14b113fbd..326b50653 100644
--- a/gen_test.go
+++ b/gen_test.go
@@ -119,11 +119,14 @@ func TestGenerate(t *testing.T) {
 func TestNegative(t *testing.T) {
 	walkTestdata(t, "_testdata/negative", func(t *testing.T, file string, data []byte) {
 		a := require.New(t)
+		_, name := path.Split(file)
 
 		spec, err := ogen.Parse(data)
 		a.NoError(err)
 
-		_, err = gen.NewGenerator(spec, gen.Options{})
+		_, err = gen.NewGenerator(spec, gen.Options{
+			Filename: name,
+		})
 		a.Error(err)
 		t.Logf("%+v", err)
 	})
diff --git a/json/location.go b/json/location.go
index 68cb5e4d1..ba631d47a 100644
--- a/json/location.go
+++ b/json/location.go
@@ -46,7 +46,7 @@ func (l Location) String() string {
 	if l.Line == 0 {
 		return strconv.Quote(l.JSONPointer)
 	}
-	return fmt.Sprintf("line %d:%d", l.Line, l.Column)
+	return fmt.Sprintf("%d:%d", l.Line, l.Column)
 }
 
 // Locatable is an interface for JSON value location store.
diff --git a/openapi/parser/errors.go b/openapi/parser/errors.go
index 1040c90fe..bb9df54ec 100644
--- a/openapi/parser/errors.go
+++ b/openapi/parser/errors.go
@@ -16,8 +16,9 @@ var _ interface {
 
 // LocationError is a wrapper for an error that has a location.
 type LocationError struct {
-	loc ogenjson.Location
-	err error
+	file string
+	loc  ogenjson.Location
+	err  error
 }
 
 // Unwrap implements errors.Wrapper.
@@ -25,15 +26,33 @@ func (e *LocationError) Unwrap() error {
 	return e.err
 }
 
+func (e *LocationError) fileName() string {
+	filename := e.file
+	if filename != "" {
+		switch {
+		case e.loc.Line != 0:
+			// Line is set, so return "${filename}:".
+			filename += ":"
+		case e.loc.JSONPointer != "":
+			// Line is not set, but JSONPointer is set, so return "${filename}#${JSONPointer}".
+			filename += "#"
+		default:
+			// Neither line nor JSONPointer is set, so return empty string.
+			return ""
+		}
+	}
+	return filename
+}
+
 // FormatError implements errors.Formatter.
 func (e *LocationError) FormatError(p errors.Printer) (next error) {
-	p.Printf("at %s", e.loc)
+	p.Printf("at %s%s", e.fileName(), e.loc)
 	return e.err
 }
 
 // Error implements error.
 func (e *LocationError) Error() string {
-	return fmt.Sprintf("at %s: %s", e.loc, e.err)
+	return fmt.Sprintf("at %s%s: %s", e.fileName(), e.loc, e.err)
 }
 
 func (p *parser) wrapLocation(l ogenjson.Locatable, err error) error {
@@ -45,7 +64,8 @@ func (p *parser) wrapLocation(l ogenjson.Locatable, err error) error {
 		return err
 	}
 	return &LocationError{
-		loc: loc,
-		err: err,
+		file: p.filename,
+		loc:  loc,
+		err:  err,
 	}
 }
diff --git a/openapi/parser/parser.go b/openapi/parser/parser.go
index 833b5ac63..341d760f8 100644
--- a/openapi/parser/parser.go
+++ b/openapi/parser/parser.go
@@ -26,6 +26,7 @@ type parser struct {
 	external   jsonschema.ExternalResolver
 	schemas    map[string][]byte
 	depthLimit int
+	filename   string // optional, used for error messages
 
 	schemaParser *jsonschema.Parser
 }
@@ -58,6 +59,7 @@ func Parse(spec *ogen.Spec, s Settings) (*openapi.API, error) {
 			"": spec.Raw,
 		},
 		depthLimit: s.DepthLimit,
+		filename:   s.Filename,
 		schemaParser: jsonschema.NewParser(jsonschema.Settings{
 			External: s.External,
 			Resolver: componentsResolver{
diff --git a/openapi/parser/resolve.go b/openapi/parser/resolve.go
index 349651906..dead26efd 100644
--- a/openapi/parser/resolve.go
+++ b/openapi/parser/resolve.go
@@ -34,7 +34,6 @@ func resolvePointer(root []byte, ptr string, to interface{}) error {
 	if err != nil {
 		return err
 	}
-
 	return json.Unmarshal(data, to)
 }
 
diff --git a/openapi/parser/settings.go b/openapi/parser/settings.go
index 2450b89ec..1bb6c5280 100644
--- a/openapi/parser/settings.go
+++ b/openapi/parser/settings.go
@@ -7,6 +7,11 @@ type Settings struct {
 	// External is external JSON Schema resolver. If nil, NoExternal resolver is used.
 	External jsonschema.ExternalResolver
 
+	// Filename is a name of the file being parsed.
+	//
+	// Used for error messages.
+	Filename string
+
 	// DepthLimit limits the number of nested references. Default is 1000.
 	DepthLimit int