diff --git a/Cargo.lock b/Cargo.lock
index 552f2d3a8..4b965fcde 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1210,9 +1210,9 @@ dependencies = [
 
 [[package]]
 name = "num-bigint"
-version = "0.4.0"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e0d047c1062aa51e256408c560894e5251f08925980e53cf1aa5bd00eec6512"
+checksum = "74e768dff5fb39a41b3bcd30bb25cf989706c90d028d1ad71971987aa309d535"
 dependencies = [
  "autocfg",
  "num-integer",
diff --git a/ast/Cargo.toml b/ast/Cargo.toml
index 24aa0e124..14b5261cd 100644
--- a/ast/Cargo.toml
+++ b/ast/Cargo.toml
@@ -10,4 +10,4 @@ constant-optimization = ["fold"]
 fold = []
 
 [dependencies]
-num-bigint = "0.4.0"
+num-bigint = "0.4.2"
diff --git a/bytecode/Cargo.toml b/bytecode/Cargo.toml
index bc901ca9f..1f8f183a4 100644
--- a/bytecode/Cargo.toml
+++ b/bytecode/Cargo.toml
@@ -12,7 +12,7 @@ license = "MIT"
 bincode =  "1.1"
 bitflags = "1.1"
 lz4_flex = "0.7"
-num-bigint = { version = "0.4.0", features = ["serde"] }
+num-bigint = { version = "0.4.2", features = ["serde"] }
 num-complex = { version = "0.4.0", features = ["serde"] }
 serde = { version = "1.0", features = ["derive"] }
 itertools = "0.10.0"
diff --git a/common/Cargo.toml b/common/Cargo.toml
index 09ca92116..bacd386af 100644
--- a/common/Cargo.toml
+++ b/common/Cargo.toml
@@ -12,7 +12,7 @@ lock_api = "0.4"
 parking_lot = { version = "0.11.0", optional = true }
 num-traits = "0.2"
 num-complex = "0.4.0"
-num-bigint = "0.4.0"
+num-bigint = "0.4.2"
 lexical-core = "0.7"
 hexf-parse = "0.1.0"
 cfg-if = "1.0"
diff --git a/parser/Cargo.toml b/parser/Cargo.toml
index b938b3a6b..fa7bf3ad2 100644
--- a/parser/Cargo.toml
+++ b/parser/Cargo.toml
@@ -15,7 +15,7 @@ lalrpop = "0.19.6"
 rustpython-ast = { path = "../ast" }
 lalrpop-util = "0.19.6"
 log = "0.4.1"
-num-bigint = "0.4.0"
+num-bigint = "0.4.2"
 num-traits = "0.2"
 unic-emoji-char = "0.9"
 unic-ucd-ident  = "0.9"
diff --git a/vm/Cargo.toml b/vm/Cargo.toml
index eaecec069..8401f2726 100644
--- a/vm/Cargo.toml
+++ b/vm/Cargo.toml
@@ -37,7 +37,7 @@ blake2 = "0.9.1"
 xml-rs = "0.8"
 
 num-complex = { version = "0.4.0", features = ["serde"] }
-num-bigint = { version = "0.4.0", features = ["serde"] }
+num-bigint = { version = "0.4.2", features = ["serde"] }
 num-traits = "0.2.8"
 num-integer = "0.1.41"
 num-rational = "0.4.0"