diff --git a/Cargo.lock b/Cargo.lock
index b11af51..3fe7de2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4056,7 +4056,7 @@ name = "node-rpc-client"
 version = "2.0.0"
 dependencies = [
  "futures 0.1.31",
- "hyper 0.12.36",
+ "hyper 0.13.10",
  "jsonrpc-core-client",
  "log",
  "node-primitives",
@@ -4213,6 +4213,17 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-bigint"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e0d047c1062aa51e256408c560894e5251f08925980e53cf1aa5bd00eec6512"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-complex"
 version = "0.2.4"
@@ -4240,7 +4251,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c000134b5dbf44adc5cb772486d335293351644b801551abe8f75c84cfa4aef"
 dependencies = [
  "autocfg",
- "num-bigint",
+ "num-bigint 0.2.6",
  "num-integer",
  "num-traits",
 ]
@@ -6740,7 +6751,7 @@ dependencies = [
  "futures-timer 3.0.2",
  "log",
  "merlin",
- "num-bigint",
+ "num-bigint 0.4.0",
  "num-rational",
  "num-traits",
  "parity-scale-codec",
@@ -8155,7 +8166,7 @@ name = "sp-arithmetic-fuzzer"
 version = "2.0.0"
 dependencies = [
  "honggfuzz",
- "num-bigint",
+ "num-bigint 0.4.0",
  "num-traits",
  "primitive-types",
  "sp-arithmetic",
diff --git a/client/consensus/babe/Cargo.toml b/client/consensus/babe/Cargo.toml
index 14d48fb..1f000c4 100644
--- a/client/consensus/babe/Cargo.toml
+++ b/client/consensus/babe/Cargo.toml
@@ -19,7 +19,7 @@ sp-consensus-babe = { version = "0.9.0", path = "../../../primitives/consensus/b
 sp-core = { version = "3.0.0", path = "../../../primitives/core" }
 sp-application-crypto = { version = "3.0.0", path = "../../../primitives/application-crypto" }
 sp-keystore = { version = "0.9.0", path = "../../../primitives/keystore" }
-num-bigint = "0.2.3"
+num-bigint = "0.4.0"
 num-rational = "0.2.2"
 num-traits = "0.2.8"
 serde = { version = "1.0.104", features = ["derive"] }
diff --git a/primitives/arithmetic/fuzzer/Cargo.toml b/primitives/arithmetic/fuzzer/Cargo.toml
index 2666dde..faf591c 100644
--- a/primitives/arithmetic/fuzzer/Cargo.toml
+++ b/primitives/arithmetic/fuzzer/Cargo.toml
@@ -17,7 +17,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 sp-arithmetic = { version = "3.0.0", path = ".." }
 honggfuzz = "0.5.49"
 primitive-types = "0.9.0"
-num-bigint = "0.2"
+num-bigint = "0.4"
 num-traits = "0.2"
 
 [[bin]]