diff --git a/balancer/grpclb/grpc_lb_v1/load_balancer.pb.go b/balancer/grpclb/grpc_lb_v1/load_balancer.pb.go
index 930f90ca..31b714db 100644
--- a/balancer/grpclb/grpc_lb_v1/load_balancer.pb.go
+++ b/balancer/grpclb/grpc_lb_v1/load_balancer.pb.go
@@ -659,11 +659,11 @@ var fileDescriptor_7cd3f6d792743fdf = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // LoadBalancerClient is the client API for LoadBalancer service.
 //
@@ -674,10 +674,10 @@ type LoadBalancerClient interface {
 }
 
 type loadBalancerClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewLoadBalancerClient(cc *grpc.ClientConn) LoadBalancerClient {
+func NewLoadBalancerClient(cc grpc.ClientConnInterface) LoadBalancerClient {
 	return &loadBalancerClient{cc}
 }
 
diff --git a/benchmark/grpc_testing/services.pb.go b/benchmark/grpc_testing/services.pb.go
index d2f7d6de..38f02540 100644
--- a/benchmark/grpc_testing/services.pb.go
+++ b/benchmark/grpc_testing/services.pb.go
@@ -49,11 +49,11 @@ var fileDescriptor_8e16ccb8c5307b32 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // BenchmarkServiceClient is the client API for BenchmarkService service.
 //
@@ -71,10 +71,10 @@ type BenchmarkServiceClient interface {
 }
 
 type benchmarkServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewBenchmarkServiceClient(cc *grpc.ClientConn) BenchmarkServiceClient {
+func NewBenchmarkServiceClient(cc grpc.ClientConnInterface) BenchmarkServiceClient {
 	return &benchmarkServiceClient{cc}
 }
 
@@ -301,10 +301,10 @@ type WorkerServiceClient interface {
 }
 
 type workerServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewWorkerServiceClient(cc *grpc.ClientConn) WorkerServiceClient {
+func NewWorkerServiceClient(cc grpc.ClientConnInterface) WorkerServiceClient {
 	return &workerServiceClient{cc}
 }
 
diff --git a/channelz/grpc_channelz_v1/channelz.pb.go b/channelz/grpc_channelz_v1/channelz.pb.go
index f5cbb3a5..34bfa5ab 100644
--- a/channelz/grpc_channelz_v1/channelz.pb.go
+++ b/channelz/grpc_channelz_v1/channelz.pb.go
@@ -2928,11 +2928,11 @@ var fileDescriptor_6ee37dfd35a8ab00 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // ChannelzClient is the client API for Channelz service.
 //
@@ -2956,10 +2956,10 @@ type ChannelzClient interface {
 }
 
 type channelzClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewChannelzClient(cc *grpc.ClientConn) ChannelzClient {
+func NewChannelzClient(cc grpc.ClientConnInterface) ChannelzClient {
 	return &channelzClient{cc}
 }
 
diff --git a/credentials/alts/internal/proto/grpc_gcp/handshaker.pb.go b/credentials/alts/internal/proto/grpc_gcp/handshaker.pb.go
index 4d1fc4c4..a2060de4 100644
--- a/credentials/alts/internal/proto/grpc_gcp/handshaker.pb.go
+++ b/credentials/alts/internal/proto/grpc_gcp/handshaker.pb.go
@@ -982,11 +982,11 @@ var fileDescriptor_54c074f40c7c7e99 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // HandshakerServiceClient is the client API for HandshakerService service.
 //
@@ -1002,10 +1002,10 @@ type HandshakerServiceClient interface {
 }
 
 type handshakerServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewHandshakerServiceClient(cc *grpc.ClientConn) HandshakerServiceClient {
+func NewHandshakerServiceClient(cc grpc.ClientConnInterface) HandshakerServiceClient {
 	return &handshakerServiceClient{cc}
 }
 
diff --git a/examples/features/proto/echo/echo.pb.go b/examples/features/proto/echo/echo.pb.go
index 4f2b7538..ccf98a68 100644
--- a/examples/features/proto/echo/echo.pb.go
+++ b/examples/features/proto/echo/echo.pb.go
@@ -132,11 +132,11 @@ var fileDescriptor_08134aea513e0001 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // EchoClient is the client API for Echo service.
 //
@@ -153,10 +153,10 @@ type EchoClient interface {
 }
 
 type echoClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewEchoClient(cc *grpc.ClientConn) EchoClient {
+func NewEchoClient(cc grpc.ClientConnInterface) EchoClient {
 	return &echoClient{cc}
 }
 
diff --git a/examples/helloworld/helloworld/helloworld.pb.go b/examples/helloworld/helloworld/helloworld.pb.go
index 0a823946..b12e92f2 100644
--- a/examples/helloworld/helloworld/helloworld.pb.go
+++ b/examples/helloworld/helloworld/helloworld.pb.go
@@ -128,11 +128,11 @@ var fileDescriptor_17b8c58d586b62f2 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // GreeterClient is the client API for Greeter service.
 //
@@ -143,10 +143,10 @@ type GreeterClient interface {
 }
 
 type greeterClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewGreeterClient(cc *grpc.ClientConn) GreeterClient {
+func NewGreeterClient(cc grpc.ClientConnInterface) GreeterClient {
 	return &greeterClient{cc}
 }
 
diff --git a/examples/route_guide/routeguide/route_guide.pb.go b/examples/route_guide/routeguide/route_guide.pb.go
index 0031144e..9536e3b5 100644
--- a/examples/route_guide/routeguide/route_guide.pb.go
+++ b/examples/route_guide/routeguide/route_guide.pb.go
@@ -342,11 +342,11 @@ var fileDescriptor_b7d679f20da65b7b = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // RouteGuideClient is the client API for RouteGuide service.
 //
@@ -379,10 +379,10 @@ type RouteGuideClient interface {
 }
 
 type routeGuideClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewRouteGuideClient(cc *grpc.ClientConn) RouteGuideClient {
+func NewRouteGuideClient(cc grpc.ClientConnInterface) RouteGuideClient {
 	return &routeGuideClient{cc}
 }
 
diff --git a/go.mod b/go.mod
index 23783613..f91583df 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/envoyproxy/protoc-gen-validate v0.1.0
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/golang/mock v1.1.1
-	github.com/golang/protobuf v1.3.2
+	github.com/golang/protobuf v1.3.3
 	github.com/google/go-cmp v0.2.0
 	golang.org/x/net v0.0.0-20190311183353-d8887717615a
 	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
diff --git a/go.sum b/go.sum
index dd5d0cee..dd0832c1 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,9 @@
 cloud.google.com/go v0.26.0 h1:e0WKqKTd5BnrG8aKH3J3h+QvEIQtSUcf2n5UZ5ZgLtQ=
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/client9/misspell v0.3.4 h1:ta993UF76GwbvJcIo3Y68y/M3WxlpEHPWIGDkJYwzJI=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473 h1:4cmBvAEBNJaGARUEs3/suWRyfyBfhf7I60WBZq+bv2w=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
@@ -14,6 +16,8 @@ github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfb
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.3 h1:gyjaxf+svBWX08ZjK86iN9geUJF0H6gp2IRKX6Nf6/I=
+github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
@@ -21,6 +25,7 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
+golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3 h1:XQyxROzUlZH+WIQwySDgnISgOivlhjIEwaQaJEJrrN0=
 golang.org/x/lint v0.0.0-20190313153728-d0100b6bd8b3/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -40,6 +45,7 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135 h1:5Beo0mZN8dRzgrMMkDp0jc8YXQKx9DiJ2k1dkvGsn5A=
 golang.org/x/tools v0.0.0-20190524140312-2c0ae7006135/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
@@ -50,4 +56,5 @@ google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc h1:/hemPrYIhOhy8zYrNj+069zDB68us2sMGsfkFJO0iZs=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
diff --git a/health/grpc_health_v1/health.pb.go b/health/grpc_health_v1/health.pb.go
index c99e27ae..4c2a527e 100644
--- a/health/grpc_health_v1/health.pb.go
+++ b/health/grpc_health_v1/health.pb.go
@@ -166,11 +166,11 @@ var fileDescriptor_e265fd9d4e077217 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // HealthClient is the client API for Health service.
 //
@@ -198,10 +198,10 @@ type HealthClient interface {
 }
 
 type healthClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewHealthClient(cc *grpc.ClientConn) HealthClient {
+func NewHealthClient(cc grpc.ClientConnInterface) HealthClient {
 	return &healthClient{cc}
 }
 
diff --git a/interop/grpc_testing/test.pb.go b/interop/grpc_testing/test.pb.go
index 507ae592..f1b522c8 100644
--- a/interop/grpc_testing/test.pb.go
+++ b/interop/grpc_testing/test.pb.go
@@ -728,11 +728,11 @@ var fileDescriptor_e1cda82041fed8bf = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // TestServiceClient is the client API for TestService service.
 //
@@ -761,10 +761,10 @@ type TestServiceClient interface {
 }
 
 type testServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewTestServiceClient(cc *grpc.ClientConn) TestServiceClient {
+func NewTestServiceClient(cc grpc.ClientConnInterface) TestServiceClient {
 	return &testServiceClient{cc}
 }
 
@@ -1149,10 +1149,10 @@ type UnimplementedServiceClient interface {
 }
 
 type unimplementedServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewUnimplementedServiceClient(cc *grpc.ClientConn) UnimplementedServiceClient {
+func NewUnimplementedServiceClient(cc grpc.ClientConnInterface) UnimplementedServiceClient {
 	return &unimplementedServiceClient{cc}
 }
 
diff --git a/profiling/proto/service.pb.go b/profiling/proto/service.pb.go
index a0d15f83..6f249372 100644
--- a/profiling/proto/service.pb.go
+++ b/profiling/proto/service.pb.go
@@ -369,11 +369,11 @@ var fileDescriptor_a0b84a42fa06f626 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // ProfilingClient is the client API for Profiling service.
 //
@@ -387,10 +387,10 @@ type ProfilingClient interface {
 }
 
 type profilingClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewProfilingClient(cc *grpc.ClientConn) ProfilingClient {
+func NewProfilingClient(cc grpc.ClientConnInterface) ProfilingClient {
 	return &profilingClient{cc}
 }
 
diff --git a/reflection/grpc_reflection_v1alpha/reflection.pb.go b/reflection/grpc_reflection_v1alpha/reflection.pb.go
index 0a12ad22..89b89622 100644
--- a/reflection/grpc_reflection_v1alpha/reflection.pb.go
+++ b/reflection/grpc_reflection_v1alpha/reflection.pb.go
@@ -635,11 +635,11 @@ var fileDescriptor_42a8ac412db3cb03 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // ServerReflectionClient is the client API for ServerReflection service.
 //
@@ -651,10 +651,10 @@ type ServerReflectionClient interface {
 }
 
 type serverReflectionClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewServerReflectionClient(cc *grpc.ClientConn) ServerReflectionClient {
+func NewServerReflectionClient(cc grpc.ClientConnInterface) ServerReflectionClient {
 	return &serverReflectionClient{cc}
 }
 
diff --git a/reflection/grpc_testing/test.pb.go b/reflection/grpc_testing/test.pb.go
index b37f0c2c..6cfb1e3f 100644
--- a/reflection/grpc_testing/test.pb.go
+++ b/reflection/grpc_testing/test.pb.go
@@ -186,11 +186,11 @@ var fileDescriptor_c161fcfdc0c3ff1e = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // SearchServiceClient is the client API for SearchService service.
 //
@@ -201,10 +201,10 @@ type SearchServiceClient interface {
 }
 
 type searchServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewSearchServiceClient(cc *grpc.ClientConn) SearchServiceClient {
+func NewSearchServiceClient(cc grpc.ClientConnInterface) SearchServiceClient {
 	return &searchServiceClient{cc}
 }
 
diff --git a/stats/grpc_testing/test.pb.go b/stats/grpc_testing/test.pb.go
index 6b853798..e040ab05 100644
--- a/stats/grpc_testing/test.pb.go
+++ b/stats/grpc_testing/test.pb.go
@@ -128,11 +128,11 @@ var fileDescriptor_e1cda82041fed8bf = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // TestServiceClient is the client API for TestService service.
 //
@@ -152,10 +152,10 @@ type TestServiceClient interface {
 }
 
 type testServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewTestServiceClient(cc *grpc.ClientConn) TestServiceClient {
+func NewTestServiceClient(cc grpc.ClientConnInterface) TestServiceClient {
 	return &testServiceClient{cc}
 }
 
diff --git a/stress/grpc_testing/metrics.pb.go b/stress/grpc_testing/metrics.pb.go
index 05bfabb1..bd5c1942 100644
--- a/stress/grpc_testing/metrics.pb.go
+++ b/stress/grpc_testing/metrics.pb.go
@@ -229,11 +229,11 @@ var fileDescriptor_6039342a2ba47b72 = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // MetricsServiceClient is the client API for MetricsService service.
 //
@@ -247,10 +247,10 @@ type MetricsServiceClient interface {
 }
 
 type metricsServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewMetricsServiceClient(cc *grpc.ClientConn) MetricsServiceClient {
+func NewMetricsServiceClient(cc grpc.ClientConnInterface) MetricsServiceClient {
 	return &metricsServiceClient{cc}
 }
 
diff --git a/test/grpc_testing/test.pb.go b/test/grpc_testing/test.pb.go
index 5daa33a2..78e9ddf5 100644
--- a/test/grpc_testing/test.pb.go
+++ b/test/grpc_testing/test.pb.go
@@ -571,11 +571,11 @@ var fileDescriptor_e1cda82041fed8bf = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // TestServiceClient is the client API for TestService service.
 //
@@ -604,10 +604,10 @@ type TestServiceClient interface {
 }
 
 type testServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewTestServiceClient(cc *grpc.ClientConn) TestServiceClient {
+func NewTestServiceClient(cc grpc.ClientConnInterface) TestServiceClient {
 	return &testServiceClient{cc}
 }
 
diff --git a/xds/internal/proto/udpa/service/orca/v1/orca.pb.go b/xds/internal/proto/udpa/service/orca/v1/orca.pb.go
index e077e1ba..990bec13 100644
--- a/xds/internal/proto/udpa/service/orca/v1/orca.pb.go
+++ b/xds/internal/proto/udpa/service/orca/v1/orca.pb.go
@@ -109,11 +109,11 @@ var fileDescriptor_f598b2ec2dba5eee = []byte{
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ context.Context
-var _ grpc.ClientConn
+var _ grpc.ClientConnInterface
 
 // This is a compile-time assertion to ensure that this generated file
 // is compatible with the grpc package it is being compiled against.
-const _ = grpc.SupportPackageIsVersion4
+const _ = grpc.SupportPackageIsVersion6
 
 // OpenRcaServiceClient is the client API for OpenRcaService service.
 //
@@ -123,10 +123,10 @@ type OpenRcaServiceClient interface {
 }
 
 type openRcaServiceClient struct {
-	cc *grpc.ClientConn
+	cc grpc.ClientConnInterface
 }
 
-func NewOpenRcaServiceClient(cc *grpc.ClientConn) OpenRcaServiceClient {
+func NewOpenRcaServiceClient(cc grpc.ClientConnInterface) OpenRcaServiceClient {
 	return &openRcaServiceClient{cc}
 }