diff --git a/Cargo.lock b/Cargo.lock
index 827bf3b99850e..7c9cc96e63571 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9094,9 +9094,9 @@ checksum = "343f3f510c2915908f155e94f17220b19ccfacf2a64a2a5d8004f2c3e311e7fd"
 
 [[package]]
 name = "syn"
-version = "1.0.48"
+version = "1.0.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc371affeffc477f42a221a1e4297aedcea33d47d19b61455588bd9d8f6b19ac"
+checksum = "a571a711dddd09019ccc628e1b17fe87c59b09d513c06c026877aa708334f37a"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/client/chain-spec/derive/Cargo.toml b/client/chain-spec/derive/Cargo.toml
index 6826168a206a5..95e1ea3bc0fe4 100644
--- a/client/chain-spec/derive/Cargo.toml
+++ b/client/chain-spec/derive/Cargo.toml
@@ -18,6 +18,6 @@ proc-macro = true
 proc-macro-crate = "0.1.4"
 proc-macro2 = "1.0.6"
 quote = "1.0.3"
-syn = "1.0.7"
+syn = "1.0.55"
 
 [dev-dependencies]
diff --git a/client/cli/proc-macro/Cargo.toml b/client/cli/proc-macro/Cargo.toml
index 9b9d134c5a836..a78fc4a79b88e 100644
--- a/client/cli/proc-macro/Cargo.toml
+++ b/client/cli/proc-macro/Cargo.toml
@@ -18,4 +18,4 @@ proc-macro = true
 proc-macro-crate = "0.1.4"
 proc-macro2 = "1.0.6"
 quote = { version = "1.0.3", features = ["proc-macro"] }
-syn = { version = "1.0.7", features = ["proc-macro", "full", "extra-traits", "parsing"] }
+syn = { version = "1.0.55", features = ["proc-macro", "full", "extra-traits", "parsing"] }
diff --git a/frame/staking/reward-curve/Cargo.toml b/frame/staking/reward-curve/Cargo.toml
index 19f7e51b8f6ce..a57e716a56f57 100644
--- a/frame/staking/reward-curve/Cargo.toml
+++ b/frame/staking/reward-curve/Cargo.toml
@@ -15,7 +15,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 proc-macro = true
 
 [dependencies]
-syn = { version = "1.0.7", features = ["full", "visit"] }
+syn = { version = "1.0.55", features = ["full", "visit"] }
 quote = "1.0.3"
 proc-macro2 = "1.0.6"
 proc-macro-crate = "0.1.4"
diff --git a/frame/support/procedural/Cargo.toml b/frame/support/procedural/Cargo.toml
index 70662d710775d..24519ef5f6357 100644
--- a/frame/support/procedural/Cargo.toml
+++ b/frame/support/procedural/Cargo.toml
@@ -18,7 +18,7 @@ proc-macro = true
 frame-support-procedural-tools = { version = "2.0.0", path = "./tools" }
 proc-macro2 = "1.0.6"
 quote = "1.0.3"
-syn = { version = "1.0.7", features = ["full"] }
+syn = { version = "1.0.55", features = ["full"] }
 
 [features]
 default = ["std"]
diff --git a/frame/support/procedural/tools/Cargo.toml b/frame/support/procedural/tools/Cargo.toml
index 2cff2473b85d4..ea528b329f327 100644
--- a/frame/support/procedural/tools/Cargo.toml
+++ b/frame/support/procedural/tools/Cargo.toml
@@ -15,5 +15,5 @@ targets = ["x86_64-unknown-linux-gnu"]
 frame-support-procedural-tools-derive = { version = "2.0.0", path = "./derive" }
 proc-macro2 = "1.0.6"
 quote = "1.0.3"
-syn = { version = "1.0.7", features = ["full", "visit"] }
+syn = { version = "1.0.55", features = ["full", "visit"] }
 proc-macro-crate = "0.1.4"
diff --git a/frame/support/procedural/tools/derive/Cargo.toml b/frame/support/procedural/tools/derive/Cargo.toml
index b616dd790d61e..d59828bd220fb 100644
--- a/frame/support/procedural/tools/derive/Cargo.toml
+++ b/frame/support/procedural/tools/derive/Cargo.toml
@@ -17,4 +17,4 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0.6"
 quote = { version = "1.0.3", features = ["proc-macro"] }
-syn = { version = "1.0.7", features = ["proc-macro" ,"full", "extra-traits", "parsing"] }
+syn = { version = "1.0.55", features = ["proc-macro" ,"full", "extra-traits", "parsing"] }
diff --git a/primitives/api/proc-macro/Cargo.toml b/primitives/api/proc-macro/Cargo.toml
index 9b1661cf5ef60..cf86dc2e27af5 100644
--- a/primitives/api/proc-macro/Cargo.toml
+++ b/primitives/api/proc-macro/Cargo.toml
@@ -18,7 +18,7 @@ proc-macro = true
 
 [dependencies]
 quote = "1.0.3"
-syn = { version = "1.0.8", features = ["full", "fold", "extra-traits", "visit"] }
+syn = { version = "1.0.55", features = ["full", "fold", "extra-traits", "visit"] }
 proc-macro2 = "1.0.6"
 blake2-rfc = { version = "0.2.18", default-features = false }
 proc-macro-crate = "0.1.4"
diff --git a/primitives/debug-derive/Cargo.toml b/primitives/debug-derive/Cargo.toml
index 10164553f857c..bcc15705919c5 100644
--- a/primitives/debug-derive/Cargo.toml
+++ b/primitives/debug-derive/Cargo.toml
@@ -18,7 +18,7 @@ proc-macro = true
 
 [dependencies]
 quote = "1.0.3"
-syn = "1.0.7"
+syn = "1.0.55"
 proc-macro2 = "1.0"
 
 [features]
diff --git a/primitives/npos-elections/compact/Cargo.toml b/primitives/npos-elections/compact/Cargo.toml
index 1873f8fa16057..e03c138535b0e 100644
--- a/primitives/npos-elections/compact/Cargo.toml
+++ b/primitives/npos-elections/compact/Cargo.toml
@@ -15,7 +15,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 proc-macro = true
 
 [dependencies]
-syn = { version = "1.0.7", features = ["full", "visit"] }
+syn = { version = "1.0.55", features = ["full", "visit"] }
 quote = "1.0"
 proc-macro2 = "1.0.6"
 proc-macro-crate = "0.1.4"
diff --git a/primitives/runtime-interface/proc-macro/Cargo.toml b/primitives/runtime-interface/proc-macro/Cargo.toml
index 8358d2170575f..abc3a6aacf583 100644
--- a/primitives/runtime-interface/proc-macro/Cargo.toml
+++ b/primitives/runtime-interface/proc-macro/Cargo.toml
@@ -16,7 +16,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 proc-macro = true
 
 [dependencies]
-syn = { version = "1.0.5", features = ["full", "visit", "fold", "extra-traits"] }
+syn = { version = "1.0.55", features = ["full", "visit", "fold", "extra-traits"] }
 quote = "1.0.3"
 proc-macro2 = "1.0.3"
 Inflector = "0.11.4"
diff --git a/test-utils/derive/Cargo.toml b/test-utils/derive/Cargo.toml
index 263bfd3537340..5a573c8c15554 100644
--- a/test-utils/derive/Cargo.toml
+++ b/test-utils/derive/Cargo.toml
@@ -10,7 +10,7 @@ description = "Substrate test utilities macros"
 
 [dependencies]
 quote = "1.0.6"
-syn = { version = "1.0.33", features = ["full"] }
+syn = { version = "1.0.55", features = ["full"] }
 proc-macro-crate = "0.1.4"
 
 [lib]