diff --git a/credentials/alts/alts.go b/credentials/alts/alts.go
index a58816565..9875d4d92 100644
--- a/credentials/alts/alts.go
+++ b/credentials/alts/alts.go
@@ -36,7 +36,7 @@ import (
 	"google.golang.org/grpc/credentials/alts/core"
 	"google.golang.org/grpc/credentials/alts/core/handshaker"
 	"google.golang.org/grpc/credentials/alts/core/handshaker/service"
-	altspb "google.golang.org/grpc/credentials/alts/core/proto"
+	altspb "google.golang.org/grpc/credentials/alts/core/proto/grpc_gcp"
 	"google.golang.org/grpc/grpclog"
 )
 
diff --git a/credentials/alts/alts_test.go b/credentials/alts/alts_test.go
index 0b8848183..9c5e7eeb1 100644
--- a/credentials/alts/alts_test.go
+++ b/credentials/alts/alts_test.go
@@ -22,7 +22,7 @@ import (
 	"testing"
 
 	"github.com/golang/protobuf/proto"
-	altspb "google.golang.org/grpc/credentials/alts/core/proto"
+	altspb "google.golang.org/grpc/credentials/alts/core/proto/grpc_gcp"
 )
 
 func TestInfoServerName(t *testing.T) {
diff --git a/credentials/alts/core/authinfo/authinfo.go b/credentials/alts/core/authinfo/authinfo.go
index 284edbff6..2fe54b74e 100644
--- a/credentials/alts/core/authinfo/authinfo.go
+++ b/credentials/alts/core/authinfo/authinfo.go
@@ -21,7 +21,7 @@ package authinfo
 
 import (
 	"google.golang.org/grpc/credentials"
-	altspb "google.golang.org/grpc/credentials/alts/core/proto"
+	altspb "google.golang.org/grpc/credentials/alts/core/proto/grpc_gcp"
 )
 
 var _ credentials.AuthInfo = (*altsAuthInfo)(nil)
diff --git a/credentials/alts/core/authinfo/authinfo_test.go b/credentials/alts/core/authinfo/authinfo_test.go
index b3d430a3c..635d80491 100644
--- a/credentials/alts/core/authinfo/authinfo_test.go
+++ b/credentials/alts/core/authinfo/authinfo_test.go
@@ -22,7 +22,7 @@ import (
 	"reflect"
 	"testing"
 
-	altspb "google.golang.org/grpc/credentials/alts/core/proto"
+	altspb "google.golang.org/grpc/credentials/alts/core/proto/grpc_gcp"
 )
 
 const (
diff --git a/credentials/alts/core/handshaker/handshaker.go b/credentials/alts/core/handshaker/handshaker.go
index ac5a3385c..d6568468d 100644
--- a/credentials/alts/core/handshaker/handshaker.go
+++ b/credentials/alts/core/handshaker/handshaker.go
@@ -33,7 +33,7 @@ import (
 	"google.golang.org/grpc/credentials/alts/core"
 	"google.golang.org/grpc/credentials/alts/core/authinfo"
 	"google.golang.org/grpc/credentials/alts/core/conn"
-	altspb "google.golang.org/grpc/credentials/alts/core/proto"
+	altspb "google.golang.org/grpc/credentials/alts/core/proto/grpc_gcp"
 )
 
 const (
diff --git a/credentials/alts/core/handshaker/handshaker_test.go b/credentials/alts/core/handshaker/handshaker_test.go
index d01cd1d95..322fcb4de 100644
--- a/credentials/alts/core/handshaker/handshaker_test.go
+++ b/credentials/alts/core/handshaker/handshaker_test.go
@@ -26,7 +26,7 @@ import (
 	"golang.org/x/net/context"
 	grpc "google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/alts/core"
-	altspb "google.golang.org/grpc/credentials/alts/core/proto"
+	altspb "google.golang.org/grpc/credentials/alts/core/proto/grpc_gcp"
 	"google.golang.org/grpc/credentials/alts/core/testutil"
 )
 
diff --git a/credentials/alts/core/proto/altscontext.pb.go b/credentials/alts/core/proto/grpc_gcp/altscontext.pb.go
similarity index 100%
rename from credentials/alts/core/proto/altscontext.pb.go
rename to credentials/alts/core/proto/grpc_gcp/altscontext.pb.go
diff --git a/credentials/alts/core/proto/altscontext.proto b/credentials/alts/core/proto/grpc_gcp/altscontext.proto
similarity index 100%
rename from credentials/alts/core/proto/altscontext.proto
rename to credentials/alts/core/proto/grpc_gcp/altscontext.proto
diff --git a/credentials/alts/core/proto/handshaker.pb.go b/credentials/alts/core/proto/grpc_gcp/handshaker.pb.go
similarity index 100%
rename from credentials/alts/core/proto/handshaker.pb.go
rename to credentials/alts/core/proto/grpc_gcp/handshaker.pb.go
diff --git a/credentials/alts/core/proto/handshaker.proto b/credentials/alts/core/proto/grpc_gcp/handshaker.proto
similarity index 100%
rename from credentials/alts/core/proto/handshaker.proto
rename to credentials/alts/core/proto/grpc_gcp/handshaker.proto
diff --git a/credentials/alts/core/proto/transport_security_common.pb.go b/credentials/alts/core/proto/grpc_gcp/transport_security_common.pb.go
similarity index 100%
rename from credentials/alts/core/proto/transport_security_common.pb.go
rename to credentials/alts/core/proto/grpc_gcp/transport_security_common.pb.go
diff --git a/credentials/alts/core/proto/transport_security_common.proto b/credentials/alts/core/proto/grpc_gcp/transport_security_common.proto
similarity index 100%
rename from credentials/alts/core/proto/transport_security_common.proto
rename to credentials/alts/core/proto/grpc_gcp/transport_security_common.proto
diff --git a/interop/alts/client/client.go b/interop/alts/client/client.go
index 0b61470a4..03feeacfc 100644
--- a/interop/alts/client/client.go
+++ b/interop/alts/client/client.go
@@ -17,7 +17,6 @@
  */
 
 // This binary can only run on Google Cloud Platform (GCP).
-
 package main
 
 import (
diff --git a/interop/alts/server/server.go b/interop/alts/server/server.go
index dcbf2c794..d4e24dfd8 100644
--- a/interop/alts/server/server.go
+++ b/interop/alts/server/server.go
@@ -17,7 +17,6 @@
  */
 
 // This binary can only run on Google Cloud Platform (GCP).
-
 package main
 
 import (