diff --git a/Cargo.toml b/Cargo.toml
index 2156949..16dd7a9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Wire Swiss GmbH <seceng@wire.com>"]
 description = "Axolotl protocol implementation"
 homepage = "https://github.com/wireapp/proteus"
 repository = "https://github.com/wireapp/proteus.git"
-license = "GPL-3.0"
+license = "GPL-3.0-only"
 edition = "2021"
 
 [workspace]
diff --git a/crates/proteus-traits/Cargo.toml b/crates/proteus-traits/Cargo.toml
index 40a8935..a23944f 100644
--- a/crates/proteus-traits/Cargo.toml
+++ b/crates/proteus-traits/Cargo.toml
@@ -6,7 +6,7 @@ description = "Traits for Proteus keystore implementation"
 homepage = "https://github.com/wireapp/proteus"
 repository = "https://github.com/wireapp/proteus.git"
 edition = "2021"
-license = "GPL-3.0"
+license = "GPL-3.0-only"
 
 [dependencies]
 async-trait = "0.1"