diff --git a/Cargo.lock b/Cargo.lock
index d7f48c17f8726..7c18cd8e7148b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4360,9 +4360,9 @@ dependencies = [
 
 [[package]]
 name = "memmap2"
-version = "0.5.8"
+version = "0.5.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b182332558b18d807c4ce1ca8ca983b34c3ee32765e47b3f0f69b90355cc1dc"
+checksum = "2af2c65375e552a67fe3829ca63e8a7c27a378a62824594f43b2851d682b5ec2"
 dependencies = [
  "libc",
 ]
diff --git a/client/chain-spec/Cargo.toml b/client/chain-spec/Cargo.toml
index 0a4e54e8d6a67..be5bb37a4da04 100644
--- a/client/chain-spec/Cargo.toml
+++ b/client/chain-spec/Cargo.toml
@@ -13,7 +13,7 @@ readme = "README.md"
 targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
-memmap2 = "0.5.0"
+memmap2 = "0.5.9"
 serde = { version = "1.0.136", features = ["derive"] }
 serde_json = "1.0.85"
 sc-chain-spec-derive = { version = "4.0.0-dev", path = "./derive" }