diff --git a/service/src/main/proto/org/signal/chat/calling.proto b/service/src/main/proto/org/signal/chat/calling.proto
index 0330dc4b9..e52858bc6 100644
--- a/service/src/main/proto/org/signal/chat/calling.proto
+++ b/service/src/main/proto/org/signal/chat/calling.proto
@@ -1,3 +1,8 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 syntax = "proto3";
 
 option java_multiple_files = true;
diff --git a/service/src/main/proto/org/signal/chat/common.proto b/service/src/main/proto/org/signal/chat/common.proto
index 5add25f6c..7d4af557d 100644
--- a/service/src/main/proto/org/signal/chat/common.proto
+++ b/service/src/main/proto/org/signal/chat/common.proto
@@ -1,3 +1,8 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 syntax = "proto3";
 
 option java_multiple_files = true;
diff --git a/service/src/main/proto/org/signal/chat/device.proto b/service/src/main/proto/org/signal/chat/device.proto
index 7842a9e40..75de93101 100644
--- a/service/src/main/proto/org/signal/chat/device.proto
+++ b/service/src/main/proto/org/signal/chat/device.proto
@@ -1,3 +1,8 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 syntax = "proto3";
 
 option java_multiple_files = true;
diff --git a/service/src/main/proto/org/signal/chat/keys.proto b/service/src/main/proto/org/signal/chat/keys.proto
index d5f06c2d6..62d09dbeb 100644
--- a/service/src/main/proto/org/signal/chat/keys.proto
+++ b/service/src/main/proto/org/signal/chat/keys.proto
@@ -1,3 +1,8 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 syntax = "proto3";
 
 option java_multiple_files = true;
diff --git a/service/src/main/proto/org/signal/chat/profile.proto b/service/src/main/proto/org/signal/chat/profile.proto
index 9cfa5cb00..8ce6609b0 100644
--- a/service/src/main/proto/org/signal/chat/profile.proto
+++ b/service/src/main/proto/org/signal/chat/profile.proto
@@ -1,3 +1,8 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
 syntax = "proto3";
 
 option java_multiple_files = true;