diff --git a/crates/dtrack-stdio/Cargo.toml b/crates/dtrack-stdio/Cargo.toml
index 809d7c8..1e14d3e 100644
--- a/crates/dtrack-stdio/Cargo.toml
+++ b/crates/dtrack-stdio/Cargo.toml
@@ -11,7 +11,9 @@ rmcp = { version = "0.16", features = ["server", "transport-io", "macros"] }
 
 tokio              = { version = "1", features = ["full"] }
 serde              = { version = "1", features = ["derive"] }
-schemars           = "0.8"
+serde_json         = "1"
+# schemars 1.x -- muss zu rmcp 0.16 passen (rmcp re-exportiert schemars 1.2).
+schemars           = "1"
 anyhow             = "1"
 tracing            = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }