diff --git a/Cargo.lock b/Cargo.lock
index 64e84fe4710af..cf4d8e39250da 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5000,6 +5000,17 @@ 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",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-complex"
 version = "0.4.0"
@@ -5036,7 +5047,7 @@ 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",
 ]
@@ -7991,7 +8002,7 @@ dependencies = [
  "futures",
  "log",
  "merlin",
- "num-bigint",
+ "num-bigint 0.4.3",
  "num-rational 0.2.4",
  "num-traits",
  "parity-scale-codec",
@@ -9496,7 +9507,7 @@ 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 e559ec165a793..fcf97873c20ff 100644
--- a/client/consensus/babe/Cargo.toml
+++ b/client/consensus/babe/Cargo.toml
@@ -21,7 +21,7 @@ codec = { package = "parity-scale-codec", version = "3.0.0", features = [
 futures = "0.3.21"
 log = "0.4.17"
 merlin = "2.0"
-num-bigint = "0.2.3"
+num-bigint = "0.4.3"
 num-rational = "0.2.2"
 num-traits = "0.2.8"
 parking_lot = "0.12.1"
diff --git a/primitives/arithmetic/fuzzer/Cargo.toml b/primitives/arithmetic/fuzzer/Cargo.toml
index 990106f990323..7e03a4dbfbd33 100644
--- a/primitives/arithmetic/fuzzer/Cargo.toml
+++ b/primitives/arithmetic/fuzzer/Cargo.toml
@@ -15,7 +15,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 honggfuzz = "0.5.49"
-num-bigint = "0.2"
+num-bigint = "0.4"
 primitive-types = "0.11.1"
 sp-arithmetic = { version = "5.0.0", path = ".." }