diff --git a/quiche/blind_sign_auth/proto/any.proto b/quiche/blind_sign_auth/proto/any.proto
index c4fa835..59e3eaf 100644
--- a/quiche/blind_sign_auth/proto/any.proto
+++ b/quiche/blind_sign_auth/proto/any.proto
@@ -16,6 +16,9 @@
 
 package quiche.protobuf;
 
+option java_multiple_files = true;
+option java_package = "com.google.privacy.ppn.proto";
+
 // Cloned from
 // https://github.com/protocolbuffers/protobuf/blob/main/src/google/protobuf/any.proto.
 message Any {
diff --git a/quiche/blind_sign_auth/proto/auth_and_sign.proto b/quiche/blind_sign_auth/proto/auth_and_sign.proto
index f3ce464..1a75f65 100644
--- a/quiche/blind_sign_auth/proto/auth_and_sign.proto
+++ b/quiche/blind_sign_auth/proto/auth_and_sign.proto
@@ -21,6 +21,9 @@
 import "quiche/blind_sign_auth/proto/proxy_layer.proto";
 import "quiche/blind_sign_auth/proto/public_metadata.proto";
 
+option java_multiple_files = true;
+option java_package = "com.google.privacy.ppn.proto";
+
 // Client is requesting to auth using the provided auth token.
 // Next ID: 17
 message AuthAndSignRequest {
diff --git a/quiche/blind_sign_auth/proto/get_initial_data.proto b/quiche/blind_sign_auth/proto/get_initial_data.proto
index c5a4d2a..627280c 100644
--- a/quiche/blind_sign_auth/proto/get_initial_data.proto
+++ b/quiche/blind_sign_auth/proto/get_initial_data.proto
@@ -22,6 +22,7 @@
 import "anonymous_tokens/proto/anonymous_tokens.proto";
 
 option java_multiple_files = true;
+option java_package = "com.google.privacy.ppn.proto";
 
 // Request data needed to prepare for AuthAndSign.
 message GetInitialDataRequest {
diff --git a/quiche/blind_sign_auth/proto/key_services.proto b/quiche/blind_sign_auth/proto/key_services.proto
index ab183c5..e75412d 100644
--- a/quiche/blind_sign_auth/proto/key_services.proto
+++ b/quiche/blind_sign_auth/proto/key_services.proto
@@ -17,6 +17,7 @@
 package privacy.ppn;
 
 option java_multiple_files = true;
+option java_package = "com.google.privacy.ppn.proto";
 
 // Indicates client's desired or capable key support.
 enum KeyType {
diff --git a/quiche/blind_sign_auth/proto/proxy_layer.proto b/quiche/blind_sign_auth/proto/proxy_layer.proto
index 4451cda..1b4895a 100644
--- a/quiche/blind_sign_auth/proto/proxy_layer.proto
+++ b/quiche/blind_sign_auth/proto/proxy_layer.proto
@@ -3,6 +3,7 @@
 package privacy.ppn;
 
 option java_multiple_files = true;
+option java_package = "com.google.privacy.ppn.proto";
 
 // Indicates which proxy layer a set of tokens will be used with.
 enum ProxyLayer {
diff --git a/quiche/blind_sign_auth/proto/public_metadata.proto b/quiche/blind_sign_auth/proto/public_metadata.proto
index 78258bb..c8da242 100644
--- a/quiche/blind_sign_auth/proto/public_metadata.proto
+++ b/quiche/blind_sign_auth/proto/public_metadata.proto
@@ -19,6 +19,7 @@
 import "anonymous_tokens/proto/anonymous_tokens.proto";
 
 option java_multiple_files = true;
+option java_package = "com.google.privacy.ppn.proto";
 
 // Contains fields which will be cryptographically linked to a blinded token and
 // visible to client, signer, and verifier. Clients should validate/set fields