diff --git a/ruma-identity-service-api/Cargo.toml b/ruma-identity-service-api/Cargo.toml
index 07f8b2ba..8f3d902a 100644
--- a/ruma-identity-service-api/Cargo.toml
+++ b/ruma-identity-service-api/Cargo.toml
@@ -17,3 +17,6 @@ ruma-identifiers = { version = "=0.18.0-alpha.1", path = "../ruma-identifiers" }
 ruma-serde = { version = "0.3.0", path = "../ruma-serde" }
 serde = { version = "1.0.118", features = ["derive"] }
 serde_json = "1.0.61"
+
+[features]
+unstable-exhaustive-types = []