diff --git a/oauth.go b/oauth.go
index d45c668..fb5ee1d 100644
--- a/oauth.go
+++ b/oauth.go
@@ -13,6 +13,7 @@ import (
 
 	"github.com/bluesky-social/indigo/atproto/atcrypto"
 	"github.com/bluesky-social/indigo/atproto/auth/oauth"
+	"github.com/bluesky-social/indigo/atproto/identity"
 	"github.com/bluesky-social/indigo/atproto/syntax"
 	"github.com/google/go-querystring/query"
 	"github.com/pkg/browser"
@@ -37,6 +38,12 @@ type OAuthConfig struct {
 
 	// AppName is an optional human-readable name included in client metadata.
 	AppName string
+
+	// Directory overrides the identity directory used to resolve handles and
+	// DIDs during the OAuth flow. If nil, indigo's default directory is used
+	// (which queries plc.directory and the public DNS). Set this to point at
+	// a test PLC (e.g. for integration tests against an ephemeral PDS).
+	Directory identity.Directory
 }
 
 // SessionInfo is returned after a successful OAuth callback.
@@ -70,6 +77,9 @@ func NewOAuthApp(cfg OAuthConfig) (*OAuthApp, error) {
 	}
 
 	app := oauth.NewClientApp(&config, store)
+	if cfg.Directory != nil {
+		app.Dir = cfg.Directory
+	}
 
 	return &OAuthApp{
 		app:     app,