diff --git a/Cargo.lock b/Cargo.lock
index c64800e002339..6eb2387651e6f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5238,6 +5238,17 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-bigint"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f93ab6289c7b344a8a9f60f88d80aa20032336fe78da341afc91c8a2341fc75f"
+dependencies = [
+ "autocfg 1.0.1",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-complex"
 version = "0.4.0"
@@ -5274,7 +5285,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c000134b5dbf44adc5cb772486d335293351644b801551abe8f75c84cfa4aef"
 dependencies = [
  "autocfg 1.0.1",
- "num-bigint",
+ "num-bigint 0.2.6",
  "num-integer",
  "num-traits",
 ]
@@ -8344,7 +8355,7 @@ dependencies = [
  "futures 0.3.21",
  "log 0.4.14",
  "merlin",
- "num-bigint",
+ "num-bigint 0.4.3",
  "num-rational 0.2.4",
  "num-traits",
  "parity-scale-codec",
@@ -9815,7 +9826,7 @@ name = "sp-arithmetic-fuzzer"
 version = "2.0.0"
 dependencies = [
  "honggfuzz",
- "num-bigint",
+ "num-bigint 0.4.3",
  "primitive-types",
  "sp-arithmetic",
 ]
diff --git a/client/consensus/babe/Cargo.toml b/client/consensus/babe/Cargo.toml
index 20cc359849f52..2313dffca9338 100644
--- a/client/consensus/babe/Cargo.toml
+++ b/client/consensus/babe/Cargo.toml
@@ -22,7 +22,7 @@ sc-consensus = { version = "0.10.0-dev", path = "../../../client/consensus/commo
 sp-core = { version = "6.0.0", path = "../../../primitives/core" }
 sp-application-crypto = { version = "6.0.0", path = "../../../primitives/application-crypto" }
 sp-keystore = { version = "0.12.0", path = "../../../primitives/keystore" }
-num-bigint = "0.2.3"
+num-bigint = "0.4.3"
 num-rational = "0.2.2"
 num-traits = "0.2.8"
 serde = { version = "1.0.136", features = ["derive"] }
diff --git a/primitives/arithmetic/fuzzer/Cargo.toml b/primitives/arithmetic/fuzzer/Cargo.toml
index e51dd4e415a6c..5255950a17bee 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 = "5.0.0", path = ".." }
 honggfuzz = "0.5.49"
 primitive-types = "0.11.1"
-num-bigint = "0.2"
+num-bigint = "0.4"
 
 [[bin]]
 name = "biguint"