diff --git a/Cargo.lock b/Cargo.lock
index 3d51a0fb1ffa4..5b82caa3c2bfb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "Inflector"
@@ -3626,7 +3626,7 @@ checksum = "848e9c511092e0daa0a35a63e8e6e475a3e8f870741448b9f6028d69b142f18e"
 dependencies = [
  "arbitrary",
  "lazy_static",
- "memmap2",
+ "memmap2 0.5.10",
  "rustc_version 0.4.0",
 ]
 
@@ -4382,9 +4382,9 @@ checksum = "884e2677b40cc8c339eaefcb701c32ef1fd2493d71118dc0ca4b6a736c93bd67"
 
 [[package]]
 name = "libc"
-version = "0.2.147"
+version = "0.2.173"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4668fb0ea861c1df094127ac5f1da3409a82116a4ba74fca2e58ef927159bb3"
+checksum = "d8cfeafaffdbc32176b64fb251369d52ea9f0a8fbc6f8759edffef7b525d64bb"
 
 [[package]]
 name = "libloading"
@@ -5145,6 +5145,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "memmap2"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd3f7eed9d3848f8b98834af67102b720745c4ec028fcd0aa0239277e7de374f"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "memoffset"
 version = "0.6.5"
@@ -7922,7 +7931,7 @@ dependencies = [
  "libc",
  "log",
  "lz4",
- "memmap2",
+ "memmap2 0.5.10",
  "parking_lot 0.12.1",
  "rand 0.8.5",
  "siphasher",
@@ -9291,7 +9300,7 @@ dependencies = [
 name = "sc-chain-spec"
 version = "4.0.0-dev"
 dependencies = [
- "memmap2",
+ "memmap2 0.9.5",
  "sc-chain-spec-derive",
  "sc-client-api",
  "sc-executor",
diff --git a/client/chain-spec/Cargo.toml b/client/chain-spec/Cargo.toml
index 1b4ce6e44605a..0e6cbd983d9a9 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 = "0.9.5"
 serde = { version = "1.0.163", features = ["derive"] }
 serde_json = "1.0.85"
 sc-client-api = { version = "4.0.0-dev", path = "../api" }