diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 21021ea0..06600144 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -17,17 +17,14 @@ prost = { version = "0.10", default-features = false, features = ["prost-derive"
 bytes = { version = "1.0.1", default-features = false }
 hex = { version = "0.4.3", default-features = false, features = [ "alloc" ] }
 anyhow = { version = "1.0.40", default-features = false }
-sp-std = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.22", default-features = false }
 sha2 = { version = "0.9.3", optional = true }
 sha3 = { version = "0.9.1", optional = true }
 ripemd160 = { version = "0.9.1", optional = true }
-sp-core = { version = "6.0.0", optional = true }
 
 [dev-dependencies]
 sha2 = { version = "0.9.3" }
 sha3 = { version = "0.9.1" }
 ripemd160 = { version = "0.9.1" }
-sp-core = { version = "6.0.0" }
 serde = { version = "1.0.125", features = ["derive"] }
 serde_json = "1.0.64"
 
@@ -38,9 +35,7 @@ std = [
     "bytes/std",
     "hex/std",
     "anyhow/std",
-    "sp-std/std",
     "sha2",
     "sha3",
     "ripemd160",
-    "sp-core",
 ]
diff --git a/rust/src/api.rs b/rust/src/api.rs
index 62481f01..4944422e 100644
--- a/rust/src/api.rs
+++ b/rust/src/api.rs
@@ -1,5 +1,5 @@
-use sp_std::collections::btree_map::BTreeMap;
-use sp_std::vec;
+use alloc::collections::btree_map::BTreeMap;
+use alloc::vec;
 
 use crate::compress::{decompress, is_compressed};
 use crate::host_functions::HostFunctionsProvider;
@@ -233,10 +233,10 @@ mod tests {
     use super::*;
 
     use alloc::string::String;
+    use alloc::vec::Vec;
     use anyhow::{bail, ensure};
     use prost::Message;
     use serde::Deserialize;
-    use sp_std::vec::Vec;
     #[cfg(feature = "std")]
     use std::fs::File;
     #[cfg(feature = "std")]
diff --git a/rust/src/compress.rs b/rust/src/compress.rs
index a3ef79ee..f18eeb3d 100644
--- a/rust/src/compress.rs
+++ b/rust/src/compress.rs
@@ -1,7 +1,7 @@
+use alloc::borrow::ToOwned;
+use alloc::collections::btree_map::BTreeMap as HashMap;
+use alloc::vec::Vec;
 use prost::Message;
-use sp_std::borrow::ToOwned;
-use sp_std::collections::btree_map::BTreeMap as HashMap;
-use sp_std::vec::Vec;
 
 use crate::helpers::Result;
 use crate::ics23;
diff --git a/rust/src/helpers.rs b/rust/src/helpers.rs
index d40220c3..36e48188 100644
--- a/rust/src/helpers.rs
+++ b/rust/src/helpers.rs
@@ -1,2 +1,2 @@
 pub type Result<T> = anyhow::Result<T>;
-pub type Hash = sp_std::vec::Vec<u8>;
+pub type Hash = alloc::vec::Vec<u8>;
diff --git a/rust/src/host_functions.rs b/rust/src/host_functions.rs
index 2c52a2b4..d68ba0fa 100644
--- a/rust/src/host_functions.rs
+++ b/rust/src/host_functions.rs
@@ -22,13 +22,16 @@ pub trait HostFunctionsProvider {
 pub mod host_functions_impl {
     use crate::host_functions::HostFunctionsProvider;
     use ripemd160::Ripemd160;
-    use sha2::{Digest, Sha512, Sha512Trunc256};
+    use sha2::{Digest, Sha256, Sha512, Sha512Trunc256};
     use sha3::Sha3_512;
 
     pub struct HostFunctionsManager;
     impl HostFunctionsProvider for HostFunctionsManager {
         fn sha2_256(message: &[u8]) -> [u8; 32] {
-            sp_core::hashing::sha2_256(message)
+            let digest = Sha256::digest(message);
+            let mut buf = [0u8; 32];
+            buf.copy_from_slice(&digest);
+            buf
         }
 
         fn sha2_512(message: &[u8]) -> [u8; 64] {
diff --git a/rust/src/ops.rs b/rust/src/ops.rs
index 7574803f..0097d89c 100644
--- a/rust/src/ops.rs
+++ b/rust/src/ops.rs
@@ -1,5 +1,5 @@
 use anyhow::{bail, ensure};
-use sp_std::convert::TryInto;
+use core::convert::TryInto;
 
 use crate::helpers::{Hash, Result};
 use crate::host_functions::HostFunctionsProvider;
@@ -80,8 +80,11 @@ fn proto_len(length: usize) -> Result<Hash> {
 #[cfg(test)]
 mod tests {
     use super::*;
+
     use crate::host_functions::host_functions_impl::HostFunctionsManager;
-    use sp_std::vec::Vec;
+
+    use alloc::vec;
+    use alloc::vec::Vec;
 
     fn decode(input: &str) -> Vec<u8> {
         hex::decode(input).unwrap()
diff --git a/rust/src/verify.rs b/rust/src/verify.rs
index 67577ebd..8d84d023 100644
--- a/rust/src/verify.rs
+++ b/rust/src/verify.rs
@@ -7,7 +7,7 @@ use crate::helpers::Result;
 use crate::host_functions::HostFunctionsProvider;
 use crate::ics23;
 use crate::ops::{apply_inner, apply_leaf};
-use sp_std::vec::Vec;
+use alloc::vec::Vec;
 
 pub type CommitmentRoot = Vec<u8>;
 
@@ -317,12 +317,13 @@ fn right_branches_are_empty(spec: &ics23::InnerSpec, op: &ics23::InnerOp) -> Res
 #[cfg(test)]
 mod tests {
     use super::*;
+
     use crate::api;
     use crate::host_functions::host_functions_impl::HostFunctionsManager;
     use crate::ics23::{ExistenceProof, HashOp, InnerOp, InnerSpec, LeafOp, LengthOp, ProofSpec};
-    use sp_std::collections::btree_map::BTreeMap as HashMap;
-    #[cfg(not(feature = "std"))]
-    use sp_std::prelude::*;
+
+    use alloc::collections::btree_map::BTreeMap as HashMap;
+    use alloc::vec;
 
     #[test]
     fn calculate_root_from_leaf() {