diff --git a/rust-config-tree-macros/Cargo.toml b/rust-config-tree-macros/Cargo.toml
index 297f1c6..bdf4f8b 100644
--- a/rust-config-tree-macros/Cargo.toml
+++ b/rust-config-tree-macros/Cargo.toml
@@ -14,4 +14,4 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1"
 quote = "1"
-syn = { version = "2", features = ["full"] }
+syn = { version = "3", features = ["full"] }