diff --git a/cumulus/Cargo.lock b/cumulus/Cargo.lock
index 26ccf4852e..b9e79306fa 100644
--- a/cumulus/Cargo.lock
+++ b/cumulus/Cargo.lock
@@ -12026,9 +12026,9 @@ checksum = "6bdef32e8150c2a081110b42772ffe7d7c9032b606bc226c8260fd97e0976601"
 
 [[package]]
 name = "syn"
-version = "1.0.99"
+version = "1.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "58dbef6ec655055e20b86b15a8cc6d439cca19b667537ac6a1369572d151ab13"
+checksum = "52205623b1b0f064a4e71182c3b18ae902267282930c6d5462c91b859668426e"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/cumulus/pallets/parachain-system/proc-macro/Cargo.toml b/cumulus/pallets/parachain-system/proc-macro/Cargo.toml
index 3debfc3ef3..1e9937d0c8 100644
--- a/cumulus/pallets/parachain-system/proc-macro/Cargo.toml
+++ b/cumulus/pallets/parachain-system/proc-macro/Cargo.toml
@@ -9,7 +9,7 @@ description = "Proc macros provided by the parachain-system pallet"
 proc-macro = true
 
 [dependencies]
-syn = "1.0.99"
+syn = "1.0.100"
 proc-macro2 = "1.0.43"
 quote = "1.0.21"
 proc-macro-crate = "1.2.1"