diff --git a/substrate/frame/contracts/proc-macro/Cargo.toml b/substrate/frame/contracts/proc-macro/Cargo.toml
index aca1d86ac2..08dafcc6a8 100644
--- a/substrate/frame/contracts/proc-macro/Cargo.toml
+++ b/substrate/frame/contracts/proc-macro/Cargo.toml
@@ -17,7 +17,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1"
 quote = "1"
-syn = "1.0.98"
+syn = { version = "1.0.98", features = ["full"] }
 
 [dev-dependencies]