diff --git a/internal/cmd/oohelper/internal/client.go b/internal/cmd/oohelper/internal/client.go
index d8de90a..7132337 100644
--- a/internal/cmd/oohelper/internal/client.go
+++ b/internal/cmd/oohelper/internal/client.go
@@ -13,7 +13,6 @@ import (
 	"github.com/apex/log"
 	"github.com/ooni/probe-cli/v3/internal/engine/experiment/webconnectivity"
 	"github.com/ooni/probe-cli/v3/internal/engine/httpheader"
-	"github.com/ooni/probe-cli/v3/internal/engine/netx"
 	"github.com/ooni/probe-cli/v3/internal/netxlite/iox"
 	"github.com/ooni/probe-cli/v3/internal/runtimex"
 	"github.com/ooni/probe-cli/v3/internal/version"
@@ -38,13 +37,18 @@ var (
 	ErrCannotParseJSONReply    = errors.New("oohelper: cannot parse JSON reply")
 )
 
+// Resolver resolves domain names.
+type Resolver interface {
+	LookupHost(ctx context.Context, hostname string) ([]string, error)
+}
+
 // OOClient is a client for the OONI Web Connectivity test helper.
 type OOClient struct {
 	// HTTPClient is the HTTP client to use.
 	HTTPClient *http.Client
 
 	// Resolver is the resolver to user.
-	Resolver netx.Resolver
+	Resolver Resolver
 }
 
 // OOConfig contains configuration for the client.