diff --git a/Cargo.lock b/Cargo.lock
index 7463db1433f0..025308bd209f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4087,6 +4087,18 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "merlin"
+version = "3.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58c38e2799fc0978b65dfff8023ec7843e2330bb462f19198840b34b6582397d"
+dependencies = [
+ "byteorder",
+ "keccak",
+ "rand_core 0.6.3",
+ "zeroize",
+]
+
 [[package]]
 name = "metered-channel"
 version = "0.9.13"
@@ -6112,7 +6124,7 @@ dependencies = [
  "kvdb",
  "kvdb-memorydb",
  "lru 0.7.1",
- "merlin",
+ "merlin 3.0.0",
  "parity-scale-codec",
  "parking_lot",
  "polkadot-node-jaeger",
@@ -8331,7 +8343,7 @@ dependencies = [
  "fork-tree",
  "futures 0.3.19",
  "log",
- "merlin",
+ "merlin 2.0.1",
  "num-bigint",
  "num-rational 0.2.4",
  "num-traits",
@@ -9092,7 +9104,7 @@ dependencies = [
  "arrayvec 0.5.2",
  "curve25519-dalek 2.1.3",
  "getrandom 0.1.16",
- "merlin",
+ "merlin 2.0.1",
  "rand 0.7.3",
  "rand_core 0.5.1",
  "sha2 0.8.2",
@@ -9577,7 +9589,7 @@ version = "0.10.0-dev"
 source = "git+https://github.com/paritytech/substrate?branch=master#b03e8bcf151bbf4c20a7d7faa782366fc3554d58"
 dependencies = [
  "async-trait",
- "merlin",
+ "merlin 2.0.1",
  "parity-scale-codec",
  "scale-info",
  "serde",
@@ -9637,7 +9649,7 @@ dependencies = [
  "lazy_static",
  "libsecp256k1",
  "log",
- "merlin",
+ "merlin 2.0.1",
  "num-traits",
  "parity-scale-codec",
  "parity-util-mem",
@@ -9795,7 +9807,7 @@ dependencies = [
  "async-trait",
  "derive_more",
  "futures 0.3.19",
- "merlin",
+ "merlin 2.0.1",
  "parity-scale-codec",
  "parking_lot",
  "schnorrkel",
diff --git a/node/core/approval-voting/Cargo.toml b/node/core/approval-voting/Cargo.toml
index 25e8c5901823..c3feca8702c0 100644
--- a/node/core/approval-voting/Cargo.toml
+++ b/node/core/approval-voting/Cargo.toml
@@ -11,7 +11,7 @@ parity-scale-codec = { version = "2.3.1", default-features = false, features = [
 tracing = "0.1.29"
 bitvec = { version = "0.20.1", default-features = false, features = ["alloc"] }
 lru = "0.7"
-merlin = "2.0"
+merlin = "3.0"
 schnorrkel = "0.9.1"
 kvdb = "0.10.0"
 derive_more = "0.99.17"