diff --git a/balancer_test.go b/balancer_test.go
index a494d6e8..77e937cb 100644
--- a/balancer_test.go
+++ b/balancer_test.go
@@ -31,11 +31,6 @@ import (
 	_ "google.golang.org/grpc/grpclog/glogger"
 	"google.golang.org/grpc/naming"
 	"google.golang.org/grpc/status"
-
-	// V1 balancer tests use passthrough resolver instead of dns.
-	// TODO(bar) remove this when removing v1 balaner entirely.
-
-	_ "google.golang.org/grpc/resolver/passthrough"
 )
 
 func pickFirstBalancerV1(r naming.Resolver) Balancer {
diff --git a/clientconn.go b/clientconn.go
index 463c7768..4414ba87 100644
--- a/clientconn.go
+++ b/clientconn.go
@@ -32,7 +32,6 @@ import (
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/balancer/base"
-	_ "google.golang.org/grpc/balancer/roundrobin" // To register roundrobin.
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
@@ -43,10 +42,12 @@ import (
 	"google.golang.org/grpc/internal/transport"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/resolver"
-	_ "google.golang.org/grpc/resolver/dns"         // To register dns resolver.
-	_ "google.golang.org/grpc/resolver/passthrough" // To register passthrough resolver.
 	"google.golang.org/grpc/serviceconfig"
 	"google.golang.org/grpc/status"
+
+	_ "google.golang.org/grpc/balancer/roundrobin"           // To register roundrobin.
+	_ "google.golang.org/grpc/internal/resolver/dns"         // To register dns resolver.
+	_ "google.golang.org/grpc/internal/resolver/passthrough" // To register passthrough resolver.
 )
 
 const (
diff --git a/clientconn_test.go b/clientconn_test.go
index 2b8b8176..02d15abb 100644
--- a/clientconn_test.go
+++ b/clientconn_test.go
@@ -39,7 +39,6 @@ import (
 	"google.golang.org/grpc/naming"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/resolver/manual"
-	_ "google.golang.org/grpc/resolver/passthrough"
 	"google.golang.org/grpc/testdata"
 )
 
diff --git a/resolver/dns/dns_resolver.go b/internal/resolver/dns/dns_resolver.go
similarity index 100%
rename from resolver/dns/dns_resolver.go
rename to internal/resolver/dns/dns_resolver.go
diff --git a/resolver/dns/dns_resolver_test.go b/internal/resolver/dns/dns_resolver_test.go
similarity index 100%
rename from resolver/dns/dns_resolver_test.go
rename to internal/resolver/dns/dns_resolver_test.go
diff --git a/resolver/passthrough/passthrough.go b/internal/resolver/passthrough/passthrough.go
similarity index 100%
rename from resolver/passthrough/passthrough.go
rename to internal/resolver/passthrough/passthrough.go
diff --git a/test/end2end_test.go b/test/end2end_test.go
index 3a450352..cbd42120 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -69,7 +69,6 @@ import (
 	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/resolver/manual"
-	_ "google.golang.org/grpc/resolver/passthrough"
 	"google.golang.org/grpc/serviceconfig"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
diff --git a/vet.sh b/vet.sh
index b2da74c0..2e7d37a2 100755
--- a/vet.sh
+++ b/vet.sh
@@ -128,7 +128,7 @@ google.golang.org/grpc/examples/features/debugging/client/main.go:SA1019
 google.golang.org/grpc/examples/features/load_balancing/client/main.go:SA1019
 google.golang.org/grpc/internal/transport/handler_server.go:SA1019
 google.golang.org/grpc/internal/transport/handler_server_test.go:SA1019
-google.golang.org/grpc/resolver/dns/dns_resolver.go:SA1019
+google.golang.org/grpc/internal/resolver/dns/dns_resolver.go:SA1019
 google.golang.org/grpc/stats/stats_test.go:SA1019
 google.golang.org/grpc/test/balancer_test.go:SA1019
 google.golang.org/grpc/test/channelz_test.go:SA1019