diff --git a/rpc/client/conn.go b/rpc/client/conn.go
index 9fc7a51..f208413 100644
--- a/rpc/client/conn.go
+++ b/rpc/client/conn.go
@@ -2,8 +2,16 @@ package client
 
 import (
 	"io"
+
+	"google.golang.org/grpc"
 )
 
+// Conn is an interface for grpc client connection.
+type Conn interface {
+	grpc.ClientConnInterface
+	io.Closer
+}
+
 // Conn returns underlying connection.
 //
 // Returns non-nil result after the first Init() call
diff --git a/rpc/client/options.go b/rpc/client/options.go
index 0575dfc..22358a3 100644
--- a/rpc/client/options.go
+++ b/rpc/client/options.go
@@ -25,7 +25,7 @@ type cfg struct {
 	tlsCfg       *tls.Config
 	grpcDialOpts []grpc.DialOption
 
-	conn *grpc.ClientConn
+	conn Conn
 }
 
 const (
@@ -114,7 +114,7 @@ func WithTLSCfg(v *tls.Config) Option {
 
 // WithGRPCConn returns option to specify
 // gRPC virtual connection.
-func WithGRPCConn(v *grpc.ClientConn) Option {
+func WithGRPCConn(v Conn) Option {
 	return func(c *cfg) {
 		if v != nil {
 			c.conn = v