diff --git a/fitsio-derive/Cargo.toml b/fitsio-derive/Cargo.toml
index 8f1c5ce4..6e020e7b 100644
--- a/fitsio-derive/Cargo.toml
+++ b/fitsio-derive/Cargo.toml
@@ -13,7 +13,7 @@ categories = ["external-ffi-bindings", "science"]
 
 [dependencies]
 quote = "1.0.0"
-syn = { version = "1.0.0", features = ["extra-traits"] }
+syn = { version = "3.0.3", features = ["extra-traits"] }
 
 [lib]
 proc-macro = true