diff --git a/Cargo.lock b/Cargo.lock
index e137851..2947c88 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -68,7 +68,7 @@ version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "006cc91e1a1d99819bc5b8214be3555c1f0611b169f527a1fdc54ed1f2b745b0"
 dependencies = [
- "core2",
+ "core2 0.3.3",
 ]
 
 [[package]]
@@ -162,9 +162,18 @@ dependencies = [
 
 [[package]]
 name = "core2"
-version = "0.3.2"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "239fa3ae9b63c2dc74bd3fa852d4792b8b305ae64eeede946265b6af62f1fff3"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "core2"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2cf12d2dad3ed124aa116f59561428478993d69ab81ae4d30e5349c9c5b5a5f6"
+checksum = "b49ba7ef1ad6107f8824dbe97de947cbaac53c44e7f9756a1fba0d37c1eec505"
 dependencies = [
  "memchr",
 ]
@@ -641,7 +650,7 @@ dependencies = [
  "arrayref",
  "bitcoin-bech32",
  "bitcoin_hashes",
- "core2",
+ "core2 0.4.0",
  "criterion",
  "digest",
  "hex",
diff --git a/mast/Cargo.toml b/mast/Cargo.toml
index adc4912..9a6af95 100644
--- a/mast/Cargo.toml
+++ b/mast/Cargo.toml
@@ -8,7 +8,7 @@ license = "GPL-3.0"
 [dependencies]
 arrayref = { version = "0.3.6", default-features = false }
 codec = { package = "parity-scale-codec", version = "3.6.5", default-features = false, features = ["derive"] }
-core2 = { version = "0.3.0", default-features = false, features = ["alloc"] }
+core2 = { version = "0.4.0", default-features = false, features = ["alloc"] }
 digest = { version = "0.9.0", default-features = false }
 rayon = { version = "1.5.0", optional = true }
 rand_core = { version = "0.6.3", default-features = false }
diff --git a/primitives/Cargo.toml b/primitives/Cargo.toml
index 6f2ce05..ea6af86 100644
--- a/primitives/Cargo.toml
+++ b/primitives/Cargo.toml
@@ -30,4 +30,4 @@ scale-info = { version = "2.10.0", default-features = false, features = ["derive
 
 impl-serde = { version = "0.4.0", default-features = false }
 impl-codec = { version = "0.6.0", default-features = false }
-primitive-types = { version = "0.12.2", default-features = false, features = ["codec", "scale-info", "num-traits", "impl-serde"] }
+primitive-types = { version = "0.12.2", default-features = false, features = ["codec", "scale-info", "num-traits"] }