diff --git a/Cargo.lock b/Cargo.lock
index a95fa816..09338e8f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -237,7 +237,7 @@ dependencies = [
  "quote",
  "serde",
  "serde_json",
- "syn 2.0.119",
+ "syn 3.0.3",
  "tempfile",
  "thiserror 2.0.19",
 ]
diff --git a/crates/llm-codegen/Cargo.toml b/crates/llm-codegen/Cargo.toml
index f9bd9ba5..68568de4 100644
--- a/crates/llm-codegen/Cargo.toml
+++ b/crates/llm-codegen/Cargo.toml
@@ -29,7 +29,7 @@ proc-macro2 = "1.0.106"
 quote = "1.0.45"
 serde = { workspace = true }
 serde_json = { workspace = true }
-syn = { version = "2.0.117", features = ["full"] }
+syn = { version = "3.0.3", features = ["full"] }
 thiserror = { workspace = true }
 utils = { package = "aether-utils", path = "../utils", version = "0.2.11" }