diff --git a/Cargo.lock b/Cargo.lock
index 15e3022bfb..730d4bcf4e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6406,7 +6406,7 @@ checksum = "848e9c511092e0daa0a35a63e8e6e475a3e8f870741448b9f6028d69b142f18e"
 dependencies = [
  "arbitrary",
  "lazy_static",
- "memmap2",
+ "memmap2 0.5.10",
  "rustc_version 0.4.0",
 ]
 
@@ -8009,6 +8009,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "memmap2"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "45fd3a57831bf88bc63f8cebc0cf956116276e97fef3966103e96416209f7c92"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "memoffset"
 version = "0.7.1"
@@ -11438,7 +11447,7 @@ dependencies = [
  "libc",
  "log",
  "lz4",
- "memmap2",
+ "memmap2 0.5.10",
  "parking_lot 0.12.1",
  "rand 0.8.5",
  "siphasher",
@@ -15437,7 +15446,7 @@ dependencies = [
  "array-bytes 6.1.0",
  "docify",
  "log",
- "memmap2",
+ "memmap2 0.9.3",
  "parity-scale-codec",
  "sc-chain-spec-derive",
  "sc-client-api",
@@ -19795,7 +19804,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "167a4ffd7c35c143fd1030aa3c2caf76ba42220bd5a6b5f4781896434723b8c3"
 dependencies = [
  "debugid",
- "memmap2",
+ "memmap2 0.5.10",
  "stable_deref_trait",
  "uuid",
 ]
diff --git a/substrate/client/chain-spec/Cargo.toml b/substrate/client/chain-spec/Cargo.toml
index 8af9e1b475..765e3e9f7c 100644
--- a/substrate/client/chain-spec/Cargo.toml
+++ b/substrate/client/chain-spec/Cargo.toml
@@ -17,7 +17,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = ["derive"] }
-memmap2 = "0.5.0"
+memmap2 = "0.9.3"
 serde = { version = "1.0.195", features = ["derive"] }
 serde_json = "1.0.111"
 sc-client-api = { path = "../api" }