diff --git a/pyo3-asyncio-macros/Cargo.toml b/pyo3-asyncio-macros/Cargo.toml
index 98df856..b0d1c69 100644
--- a/pyo3-asyncio-macros/Cargo.toml
+++ b/pyo3-asyncio-macros/Cargo.toml
@@ -21,4 +21,4 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1"
-syn = { version = "1", features = ["full"] }
+syn = { version = "2", features = ["full"] }